Make tap gesture recognizer public on annotation managers + clean up

[nishant-karajgikar]

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• Briefly describe the changes in this PR.
• Include before/after visuals or gifs if this PR includes visual changes.
• Write tests for all new functionality. If tests were not written, please explain why.
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Summary of changes

This PR makes the following changes:

• The tapRecognizer on annotation managers is now public. It can be used to coordinate with custom gestures that a developer may want to add on the map.
• Annotations no longer have a type var since it's redundant.