Replace link with button in "Invalidate Caches..." dialog

[a-narsudinov]

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Current implementation of the "Just restart" element as a link instead of button looks awkward to me, moreover according to the JB UI guideline element that perform immediate action should be a button, not a link.

This patch replaces the link element with a button.

Dialog menu before the patch

And after (checkboxes are not related to the PR changes, I have no idea why they have disappeared)

[a-narsudinov]

Hello! Any updates? It would be nice to merge because the current link-style button feels broken.

[a-narsudinov]

Hi there! More than a year has passed and this menu is still the same and feels broken.

@jonnyzzz @bulenkov could you please have a look?