Enh: Allow "Like" on non-content objects

[marc-farre]

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change? (check one)

• Yes
• No

If yes, please describe the impact and migration path for existing applications:

The PR fulfills these requirements:

• It's submitted to the develop branch, not the master branch if no hotfix
• When resolving a specific issue, it's referenced in the PR's description (e.g. Fix #xxx[,#xxx], where "xxx" is the Github issue number)
• All tests are passing
• New/updated tests are included
• Changelog was modified

If adding a new feature, the PR's description includes:

• A convincing reason for adding this feature (to avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it)

Other information:

Issue humhub/mail#188

[what-the-diff]

PR Summary

This PR introduces the ability for users to like non-content objects within the application along with corresponding notifications and view updates.

• Introduced "Like" feature for non-content objects
  These updates enable users to engage with various components across the platform by liking them, increasing interactivity.

• Implemented LikeNotificationInterface interface
  This new interface enables classes to be "Liked", paving the way for more dynamic interactions.

• Updated Like model to support content and content addons
  The changes enhance the existing "Like" functionality to accommodate both content and content addons, expanding its reach to more areas of the platform.

• Created LikeController to manage likes
  This new controller handles the logic for liking and unliking objects, making sure everything works smoothly from a backend perspective.

• Added a NewLike notification
  Users will now receive notifications when someone likes their posts, improving user experience by keeping them up-to-date with interactions on their content.

• Designed new views for the NewLike Notification Email
  Users are now able to see their "like" notifications through their emails, which will keep them informed about interactions even when they are not on the platform.

• Modified the LikeLink Widget
  The 'Like' feature has been seamlessly integrated into the existing interface, ensuring a user-friendly experience.