Unify logic for credentials (GONRG-539)

Description:

• Credential classes were moved into gcp-core-lib.
• Changed a version 'gcp-core-lib'.
• Changed unit tests.

How to test:

Check business logic.

Changes include:

• Refactor (a non-breaking change that improves code maintainability).
• Bugfix (a non-breaking change that solves an issue).
• New feature (a non-breaking change that adds functionality).
• Breaking change (a change that is not backward-compatible and/or changes current functionality).

Changes in:

• GCP
• Azure
• AWS
• IBM

Dev Checklist:

• Added Unit Tests, wherever applicable.
• Updated the Readme, if applicable.
• Existing Tests pass
• Verified functionality locally
• Self Reviewed my code for formatting and complex business logic.

Other comments:

Any comments to approvers here

provider/legal-gcp/src/main/java/org/opengroup/osdu/legal/di/DatastoreCredentialsCacheFactory.java

+package org.opengroup.osdu.legal.di;
+
+import org.opengroup.osdu.core.common.cache.ICache;
+import org.opengroup.osdu.core.common.cache.VmCache;
+import org.opengroup.osdu.core.gcp.multitenancy.credentials.DatastoreCredential;
+import org.springframework.beans.factory.config.AbstractFactoryBean;
+import org.springframework.stereotype.Component;
+
+@Component
+public class DatastoreCredentialsCacheFactory extends
+    AbstractFactoryBean<ICache<String, DatastoreCredential>> {
+
+  @Override
+  public Class<?> getObjectType() {
+    return ICache.class;
+  }
+
+  @Override
+  protected ICache<String, DatastoreCredential> createInstance() throws Exception {
+    return new VmCache<>(5 * 60, 20);
+  }
+}
+