Added IndexMetadataModel to metadata lib along with other required dependencies

Signed-off-by: Manik Garg <gargmanik1317@gmail.com>

Author: gargmanik13

libs/metadata/src/main/java/org/opensearch/metadata/index/model/AliasMetadataModel.java

@@ -268,6 +268,20 @@ public Builder(String alias) {
             this.alias = Objects.requireNonNull(alias, "alias must not be null");
         }
 
+        /**
+         * Creates a new builder from an existing {@link AliasMetadataModel}.
+         *
+         * @param model the model to copy from
+         */
+        public Builder(AliasMetadataModel model) {
+            this.alias = model.alias();
+            this.filter = model.filter();
+            this.indexRouting = model.indexRouting();
+            this.searchRouting = model.searchRouting();
+            this.writeIndex = model.writeIndex();
+            this.isHidden = model.isHidden();
+        }
+
         /**
          * Returns the alias name from builder.
          *

libs/metadata/src/main/java/org/opensearch/metadata/index/model/ContextModel.java

@@ -0,0 +1,110 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.metadata.index.model;
+
+import org.opensearch.common.annotation.ExperimentalApi;
+import org.opensearch.core.common.io.stream.StreamInput;
+import org.opensearch.core.common.io.stream.StreamOutput;
+import org.opensearch.core.common.io.stream.Writeable;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.Objects;
+
+/**
+ * A model class for Context metadata that can be used in metadata lib without
+ * depending on the full Context class from server module.
+ */
+@ExperimentalApi
+public final class ContextModel implements Writeable {
+
+    private final String name;
+    private final String version;
+    private final Map<String, Object> params;
+
+    /**
+     * Creates a ContextModel with the given fields.
+     *
+     * @param name the context name
+     * @param version the context version
+     * @param params the context parameters
+     */
+    public ContextModel(String name, String version, Map<String, Object> params) {
+        this.name = name;
+        this.version = version;
+        this.params = params;
+    }
+
+    /**
+     * Creates a ContextModel by reading from StreamInput.
+     * Wire format is compatible with Context(StreamInput).
+     *
+     * @param in the stream to read from
+     * @throws IOException if an I/O error occurs
+     */
+    public ContextModel(StreamInput in) throws IOException {
+        this.name = in.readString();
+        this.version = in.readOptionalString();
+        this.params = in.readMap();
+    }
+
+    /**
+     * Writes to StreamOutput.
+     * Wire format is compatible with Context.writeTo.
+     *
+     * @param out the stream to write to
+     * @throws IOException if an I/O error occurs
+     */
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        out.writeString(name);
+        out.writeOptionalString(version);
+        out.writeMap(params);
+    }
+
+    /**
+     * Returns the context name.
+     *
+     * @return the name
+     */
+    public String name() {
+        return name;
+    }
+
+    /**
+     * Returns the context version.
+     *
+     * @return the version
+     */
+    public String version() {
+        return version;
+    }
+
+    /**
+     * Returns the context parameters.
+     *
+     * @return the params map
+     */
+    public Map<String, Object> params() {
+        return params;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        ContextModel that = (ContextModel) o;
+        return Objects.equals(name, that.name) && Objects.equals(version, that.version) && Objects.equals(params, that.params);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(name, version, params);
+    }
+}