[DataFactory]Add support OAuth2ClientCredential auth in RestSevice (#19247)

* [DataFactory]Added privateEndpoint Into PrivateLinkConnectionApprovalRequest

* update

* [DataFactory]Add support OAuth2ClientCredential auth in RestSevice

* merge

Author: Jingshu923

specification/datafactory/resource-manager/Microsoft.DataFactory/stable/2018-06-01/entityTypes/LinkedService.json

@@ -2909,7 +2909,8 @@
             "Anonymous",
             "Basic",
             "AadServicePrincipal",
-            "ManagedServiceIdentity"
+            "ManagedServiceIdentity",
+            "OAuth2ClientCredential"
           ],
           "x-ms-enum": {
             "name": "RestServiceAuthenticationType",
@@ -2955,6 +2956,26 @@
         "credential": {
           "$ref": "../datafactory.json#/definitions/CredentialReference",
           "description": "The credential reference containing authentication information."
+        },
+        "clientId": {
+          "type": "object",
+          "description": "The client ID associated with your application. Type: string (or Expression with resultType string)."
+        },
+        "clientSecret": {
+          "description": "The client secret associated with your application.",
+          "$ref": "../datafactory.json#/definitions/SecretBase"
+        },
+        "tokenEndpoint": {
+          "type": "object",
+          "description": "The token endpoint of the authorization server to acquire access token. Type: string (or Expression with resultType string)."
+        },
+        "resource": {
+          "type": "object",
+          "description": "The target service or resource to which the access will be requested. Type: string (or Expression with resultType string)."
+        },
+        "scope": {
+          "type": "object",
+          "description": "The scope of the access required. It describes what kind of access will be requested. Type: string (or Expression with resultType string)."
         }
       },
       "required": [

specification/synapse/data-plane/Microsoft.Synapse/preview/2021-06-01-preview/entityTypes/LinkedService.json

@@ -2729,7 +2729,8 @@
             "Anonymous",
             "Basic",
             "AadServicePrincipal",
-            "ManagedServiceIdentity"
+            "ManagedServiceIdentity",
+            "OAuth2ClientCredential"
           ],
           "x-ms-enum": {
             "name": "RestServiceAuthenticationType",
@@ -2767,6 +2768,26 @@
         "encryptedCredential": {
           "description": "The encrypted credential used for authentication. Credentials are encrypted using the integration runtime credential manager. Type: string (or Expression with resultType string).",
           "type": "object"
+        },
+        "clientId": {
+          "type": "object",
+          "description": "The client ID associated with your application. Type: string (or Expression with resultType string)."
+        },
+        "clientSecret": {
+          "description": "The client secret associated with your application.",
+          "$ref": "../artifacts.json#/definitions/SecretBase"
+        },
+        "tokenEndpoint": {
+          "type": "object",
+          "description": "The token endpoint of the authorization server to acquire access token. Type: string (or Expression with resultType string)."
+        },
+        "resource": {
+          "type": "object",
+          "description": "The target service or resource to which the access will be requested. Type: string (or Expression with resultType string)."
+        },
+        "scope": {
+          "type": "object",
+          "description": "The scope of the access required. It describes what kind of access will be requested. Type: string (or Expression with resultType string)."
         }
       },
       "required": [

specification/synapse/data-plane/Microsoft.Synapse/stable/2020-12-01/entityTypes/LinkedService.json

@@ -2729,7 +2729,8 @@
             "Anonymous",
             "Basic",
             "AadServicePrincipal",
-            "ManagedServiceIdentity"
+            "ManagedServiceIdentity",
+            "OAuth2ClientCredential"
           ],
           "x-ms-enum": {
             "name": "RestServiceAuthenticationType",
@@ -2767,6 +2768,26 @@
         "encryptedCredential": {
           "description": "The encrypted credential used for authentication. Credentials are encrypted using the integration runtime credential manager. Type: string (or Expression with resultType string).",
           "type": "object"
+        },
+        "clientId": {
+          "type": "object",
+          "description": "The client ID associated with your application. Type: string (or Expression with resultType string)."
+        },
+        "clientSecret": {
+          "description": "The client secret associated with your application.",
+          "$ref": "../artifacts.json#/definitions/SecretBase"
+        },
+        "tokenEndpoint": {
+          "type": "object",
+          "description": "The token endpoint of the authorization server to acquire access token. Type: string (or Expression with resultType string)."
+        },
+        "resource": {
+          "type": "object",
+          "description": "The target service or resource to which the access will be requested. Type: string (or Expression with resultType string)."
+        },
+        "scope": {
+          "type": "object",
+          "description": "The scope of the access required. It describes what kind of access will be requested. Type: string (or Expression with resultType string)."
         }
       },
       "required": [