CLDCONNECT-1668 Build connector with devkit 3.5.0 & Migrate functional test cases from 3.4.x to 3.5.0

Upgraded Mule Devkit to 3.5.0.
Removed @Optional as it is redundant when used along @Default.
Removed deprecated @OAuthInvalidateAccessTokenOn and added @ReconnectOn on the Connector.
Fixed all the functional test cases for devkit 3.5.0
Updated CHANGELOG.md