feature: Add mouse support to sorting columns

[ClementTsang]

Description

A description of the change and what it does. If relevant, please provide screenshots of what results from the change:

Adds mouse support for sorting columns within the process widget. You can now click on the column header to sort (or invert the sort).

bottom.mouse.sort.support.mp4

Issue

If applicable, what issue does this address?

Closes: #395

Type of change

Remove the irrelevant ones:

• New feature (non-breaking change which adds functionality)

Test methodology

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Furthermore, please tick which platforms this change was tested on:

• Windows
• macOS
• Linux

If relevant, all of these platforms should be tested.

Checklist

If relevant, ensure the following have been met:

• Change has been tested to work, and does not cause new breakage unless intended
• Code has been self-reviewed
• Documentation has been added/updated if needed (README, help menu, etc.)
• Passes CI pipeline (clippy check and cargo test check)
• Areas your change affects have been linted using rustfmt (cargo fmt)
• No merge conflicts arise from the change

Other information

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