Add Draw Square From Center mode

[StijnAmeloot]

Adds new edit mode which allows the user to draw a square from the center.
It's possible to draw a square by clicking twice or by dragging (dragToDraw set to true).

Demo

[coveralls]

Pull Request Test Coverage Report for Build 2302

• 0 of 25 (0.0%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.1%) to 22.048%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
modules/edit-modes/src/index.ts	0	1	0.0%
modules/main/src/index.ts	0	1	0.0%
modules/edit-modes/src/lib/draw-square-from-center-mode.ts	0	23	0.0%

Totals
Change from base Build 2294:	-0.1%
Covered Lines:	1218
Relevant Lines:	5224

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💛 - Coveralls