Add ephemeral resource support

[modular-magician]

Add basic support for ephemeral resources

• Add dependency on branch in https://github.com/hashicorp/terraform-plugin-framework that contains necessary features
  • go get github.com/hashicorp/terraform-plugin-framework@fe2b7dbbdad8ac4e45efee7e4a9eb1fd08003fcf
    • Need to use a commit due to the branch name containing a forward slash
  • We will change this before merging the overall feature branch, but using this during development is fine!
• Implemented this interface
• Currently there are no test environments (PR automation, TeamCity) that can utilise ephemeral values

Merging this PR into the feature branch will enable working on multiple ephemeral resources in separate PRs at once.

Release Note Template for Downstream PRs (will be copied)

Derived from GoogleCloudPlatform/magic-modules#11843