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

[josemarinas]

Description

• [x] is upgradeable, but it doesn’t have a storage gap
• [x] 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
• [x] We miss a test checking that function updateReleaseMetadata emits the ReleaseMetadataUpdated event
• [x] 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.

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

Checklist:

• [x] I have selected the correct base branch.
• [x] I have performed a self-review of my own code.
• [x] I have commented my code, particularly in hard-to-understand areas.
• [x] My changes generate no new warnings.
• [ ] Any dependent changes have been merged and published in downstream modules.
• [x] 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.