Add builder method to add a configuration store. (#67)

Author: leoromanovsky

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@eppo/js-client-sdk-common",
-  "version": "3.0.7",
+  "version": "3.0.8",
   "description": "Eppo SDK for client-side JavaScript applications (base for both web and react native)",
   "main": "dist/index.js",
   "files": [

src/client/eppo-client.ts

@@ -87,6 +87,8 @@ export interface IEppoClient {
     configurationRequestParameters: FlagConfigurationRequestParameters,
   ): void;
 
+  setConfigurationStore(configurationStore: IConfigurationStore<Flag | ObfuscatedFlag>): void;
+
   fetchFlagConfigurations(): void;
 
   stopPolling(): void;
@@ -140,6 +142,10 @@ export default class EppoClient implements IEppoClient {
     this.configurationRequestParameters = configurationRequestParameters;
   }
 
+  public setConfigurationStore(configurationStore: IConfigurationStore<Flag | ObfuscatedFlag>) {
+    this.configurationStore = configurationStore;
+  }
+
   public async fetchFlagConfigurations() {
     if (!this.configurationRequestParameters) {
       throw new Error(