Add a way to hide columns in the download table

[heldersepu]

This PR adds a simple way to hide columns in the download table

right clicking in the header header().customContextMenuRequested, will show a small menu
in that menu we have options:

• allow the users to hide the clicked column header().hideSection(index)
• restore all hidden columns

[github-actions]

Hi @heldersepu, thank you for contributing to Tribler! 🚀

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[kozlovsky]

Thank you for the PR. While hiding a column can be useful for some users, the way it is implemented has some usability issues:

• Unexpected Behavior: Double-clicking a column header typically relates to sorting or adjusting the width of the column in many applications. Hiding a column by double-clicking could be counterintuitive for users accustomed to standard UI patterns.

• Accidental Clicks: Users might accidentally double-click a header, expecting it to sort or adjust, and instead find the column has disappeared. Imagine the Name column disappears after a user accidentally double-clicks it. This could lead to confusion and frustration. It may be hard for a user to understand what has just happened, and it will look like a bug.

• Lack of Reversibility: The absence of an immediate way to bring back the hidden column without restarting the application is a significant usability issue. Users should have the ability to easily undo the action, ideally through the same interface mechanism used to hide it (e.g., right-click the context menu to show/hide columns).

A more intuitive approach might be to implement a right-click context menu on the column headers. This would not only prevent accidental hiding but also enhance functionality by giving users more control.

[heldersepu]

@kozlovsky right-click context menu added

[kozlovsky]

It looks good, but one fix should be added.

After you apply the fix, can you please squash all commits in the PR branch to make the commit history easier to read?

[heldersepu]

After you apply the fix, can you please squash all commits in the PR branch to make the commit history easier to read?

Fix applied, and all commits have been squashed

[kozlovsky]

Great, thank you for the contribution!