Clipboard copy enhancements (#27669)

Clipboard copy enhancements (#27669)

1. Do not show temporary tooltips that are triggered from within
dropdowns. Previously this resulted in the tooltip being stuck to
top-left of the page like seen on issue comment URL copy. I could not
figure out any tippy options that prevent this, so I think it's better
to just not show it.
1. Refactor `initGlobalCopyToClipboardListener` so that it does not run
a often useless `document.querySelector` on every click, make
`data-clipboard-text-type` work with `data-clipboard-target`. No use in
current code base but still good to have. Finally some minor code
cleanup in the function.

Point 1 is for this copy button:

<img width="229" alt="image"
src="https://github.com/go-gitea/gitea/assets/115237/81f34746-8ea5-43d9-8c6f-f6f417a9e4ad">

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Co-authored-by: Giteabot <teabot@gitea.io>