PR: Fix some issues with the profiler

[goanpeca]

Description of Changes

• Included a screenshot or animation (if affecting the UI, see Licecap)

• The icons no longer have text next to them
• In macOS icons don’t have tooltips.
• The combobox in master is really small and it truncates the whole path of the file.

In macOS when I hit the option to expand all, the last entry is not visible even in the bottom of the scrollbar

I cannot reproduce this, see GIF

Issue(s) Resolved

Fixes #13698

Affirmation

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and understand I am releasing the same under Spyder's MIT (Expat) license.

I certify the above statement is true and correct: @goanpeca

[juanis2112]

Thanks for fixing this @goanpeca. Can you also please remove the text next to the browse icon? It wasn't originally in 4.x so I think for now it should be removed.

Finally I also noticed that the "Clear comparison" is available by default and in 4.x it is only available when there is actually some diff loaded which I think makes more sense. Can you fix this too?

[dalthviz]

@ccordoba12 checking the failing test is unrelated to the changes done here. Seems like pandas 1.2.0 was released on December 26th and that is causing an error in the CollectionsEditor tests running under a pip installation). Besides that I think this is ready for review 👍

[ccordoba12]

Thanks @goanpeca and @dalthviz for your work on this one.

Review was addressed