Integrate Robot with screencopy

[hbatagelo]

This PR proposes a Robot library (Screencopy.py) that provides keywords for matching image templates with frames captured from the Wayland display. The keywords are:

• Test Match [template]: Grabs a screenshot and checks for a match with a given template. The result is a list of matching regions, each represented as a dictionary with left, top, right, and bottom keys.
• Wait Match [template] [timeout]: Grabs a screenshot and waits until there is a match. The result is a list of matching regions.

For both, if no match is found, an exception is raised, and the screenshot and the template are written to the Robot log.

The following additional keywords are available in screencopy.resource:

• Get Center [region]: Calculates the center of a region. The return value is a point (a dictionary with x and y keys).
• Add Displacement [point] [displacement_x] [displacement_y]: Adds a displacement to the given point. The return value is also a point.

An example of these keywords in action is given in test_drag_and_drop.py.

[codecov[bot]]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (b38a64f) 64.64% compared to head (2e7aa1b) 64.46%.

Files	Patch %	Lines
mir-ci/mir_ci/screencopy_tracker.py	0.00%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #62 +/- ## ========================================== - Coverage 64.64% 64.46% -0.18% ========================================== Files 11 11 Lines 724 726 +2 Branches 88 88 ========================================== Hits 468 468 - Misses 233 235 +2 Partials 23 23 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[hbatagelo]

I've changed grab_screenshot to look for the next frame (this will fix issue #66) and have added the timeout. Seems to work well.