Allow image uploads to be optimised to reduce bandwidth.

[pixlwave]

Follow on from #3408 and part of #3398, this PR implements the changes for image processing. I've re-written the processor quite a bit so this PR is broken down into chunks to make it easier to review.

Things to note:

• We don't need to worry about potentially upscaling, CoreGraphics happily ignores that for us.
• We optimise HEIC files as JPEG, but send them as HEIC when unoptimised.
• We optimise PNGs as PNG to retain alpha and better compression of screenshots.
• We don't optimise GIFs as it would destroy the animation.
• All other image types are optimised as JPEG.

[github-actions]

	Warnings
⚠️	Some of the commits are missing ticket numbers. Please consider squashing all commits that don't have a tracking number.

Generated by 🚫 Danger Swift against f7b9c0d

[codecov]

❌ 2 Tests Failed:

Tests completed	Failed	Passed	Skipped
845	2	843	0

View the full list of 2 ❄️ flaky tests

PreviewTests test_joinRoomScreen()

Flake rate in main: 15.38% (Passed 22 times, Failed 4 times)

Stack Traces | 3.38s run time

failed - Snapshot "Unknown" does not match reference.

@−
"file:.../__Snapshots__/PreviewTests/test_joinRoomScreen-iPhone-16-en-GB.Unknown.png"
@+
"file:.../tmp/PreviewTests/test_joinRoomScreen-iPhone-16-en-GB.Unknown.png"

To configure output for a custom diff tool, use 'withSnapshotTesting'. For example:

    withSnapshotTesting(diffTool: .ksdiff) {
      // ...
    }

The percentage of pixels that match 0.9661255 is less than required 1.0
The lowest perceptual color precision 0.39999998 is less than required 0.98 (.../PreviewTests/Sources/PreviewTests.swift:84)

PreviewTests test_roomMemberDetailsScreen()

Flake rate in main: 19.21% (Passed 328 times, Failed 78 times)

Stack Traces | 3.73s run time

failed - Snapshot "Other User" does not match reference.

@−
"file:.../__Snapshots__/PreviewTests/test_roomMemberDetailsScreen-iPhone-16-en-GB.Other-User.png"
@+
"file:.../tmp/PreviewTests/test_roomMemberDetailsScreen-iPhone-16-en-GB.Other-User.png"

To configure output for a custom diff tool, use 'withSnapshotTesting'. For example:

    withSnapshotTesting(diffTool: .ksdiff) {
      // ...
    }

The percentage of pixels that match 0.85461426 is less than required 1.0
The lowest perceptual color precision 0.148125 is less than required 0.98 (.../PreviewTests/Sources/PreviewTests.swift:84)

To view individual test run time comparison to the main branch, go to the Test Analytics Dashboard

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud