Feature #25410: Image capture

[prodoelmit]

Resolves: #25410 (Partially)

Brings back functionality of Image Capture (aka Camera)

This PR should be treated as technical implementation with no intent to be final well-designed tool. It works, but it's not pretty. It only supports PNG/SVG yet

• I signed the CLA
• The title of the PR describes the problem it addresses
• Each commit's message describes its purpose and effects, and references the issue it resolves
• If changes are extensive, there is a sequence of easily reviewable commits
• The code in the PR follows the coding rules
• There are no unnecessary changes
• The code compiles and runs on my machine, preferably after each commit individually
• I created a unit test or vtest to verify the changes I made (if applicable)

[avvvvve]

@prodoelmit, can you attach a video of how to use this?

I'm on macOS and have tried toggling "Capture mode" on and off and changing format, but the export button is always disabled. I tried clicking and dragging on the score in capture mode and nothing happened. Do I need to use some keyboard shortcuts?

[prodoelmit]

@avvvvve my bad, at the time of posting I got too used to it so that it became obvious for me :)

It currently uses the Lasso tool logic, so it's Shift+click&drag

https://youtu.be/MMLbscUvWLY