refactor: added reinitializer and storage gap to PluginRepo and moved events to IPluginRepo

[josemarinas]

Description

• is upgradeable, but it doesn’t have a storage gap
• Why are the events VersionCreated and ReleaseMetadataUpdated in PluginRepo and not in the IPluginRepo Interface?
  • we can move the events to the right place without changing the ERC-165 interface ID and updating the PluginRepoFactory
• We miss a test checking that function updateReleaseMetadata emits the ReleaseMetadataUpdated event
• Add an initializeFrom function to the contract. (see )
  • check on DAO.sol how this function is supposed to work
  • if we don’t need to re-initialize, then this function will be empty for now.

Task ID: OS-676

Type of change

See the framework lifecycle in packages/contracts/docs/framework-lifecycle to decide what kind of change this pull request is.

• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• I have selected the correct base branch.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• My changes generate no new warnings.
• Any dependent changes have been merged and published in downstream modules.
• I ran all tests with success and extended them if necessary.
• I have updated the CHANGELOG.md file in the root folder.
• I have updated the DEPLOYMENT_CHECKLIST file in the root folder.
• I have updated the UPDATE_CHECKLIST file in the root folder.
• I have updated the Subgraph and added a QA URL to the description of this PR.

[heueristik]

LGTM