[Identity] Move the common files between Identity and Identity plugins to a shared location

[KarishmaGhiya]

We are running into build issues for upgrading the versions of identity. Here's the summary:

In the CI, the plugin packages identity-vscode and identity-cache-persistence are built first. Adn these import AzurePluginContext directly from the source files of identity package. The semver version dependency of these packages depend on the 2.0.x versions of identity and upgrading the local version of identity package - no longer satisfies the semver dependency for identity on these plugin packages.
The errors about not being able to find core packages are coming from the src files of identity - that is not yet built and is being pulled in from the src files of the plugin packages. If the reference to AzurePluginContext in the plugin packages was made from the identity package instead of directly importing src files of identity, then we probably would not have run into this issue. It thinks that the identity src files are it's own package files and ofcourse we don't have these core packages as dependencies in the plugin packages.

[github-actions]

Hi @KarishmaGhiya, we deeply appreciate your input into this project. Regrettably, this issue has remained inactive for over 2 years, leading us to the decision to close it. We've implemented this policy to maintain the relevance of our issue queue and facilitate easier navigation for new contributors. If you still believe this topic requires attention, please feel free to create a new issue, referencing this one. Thank you for your understanding and ongoing support.