Move center to marker when clicked

[Emojigit]

This PR adds code to move the center of the canvas to where it is when a marker is clicked. There are some limitations:

• Only AbstractIconOverlay is supported. I am too lazy to make others because the implementation differs between non-AbstractIconOverlay markers.
• If moving the map results in loading new tiles, the movement may be disturbed. The reason is still unknown.

As usual, this PR can be tested on my map server. This PR is ready for review. And yeah, I used 10 commits before eventually passing the finish line.

[coveralls]

Pull Request Test Coverage Report for Build 9419841347

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 67.636%

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Totals
Change from base Build 9405508814:	0.0%
Covered Lines:	907
Relevant Lines:	1341

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💛 - Coveralls

[Emojigit]

This can be an opt-in feature if that would be better, but I am not sure exactly how to do that.

[BuckarooBanzay]

And yeah, I used 10 commits before eventually passing the finish line.

no worries 😆

looks good, thanks 👍