Outsource initialization of Bootstrap popovers (Fix "New comment" button)

[Frodo161]

This branch fixes issue #524: Open the show_comment page. Hit the "new comment" button, then click "abort". Hitting the "new comment" button again won't have any effect now.

The problem is that two variables in the edit javascript file are declared as constants while hitting the button twice causes them to be redefined.

Changing the variable declaration from "const" to "var" won't cause any problems in this situation and fixes the bug.

[codecov]

Codecov Report

Merging #534 (1ebeaeb) into mampf-next (883417c) will not change coverage.
Report is 1 commits behind head on mampf-next.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           mampf-next     #534   +/-   ##
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  Coverage       66.48%   66.48%           
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  Files             311      311           
  Lines            9417     9417           
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  Hits             6261     6261           
  Misses           3156     3156           

[Splines]

@Frodo161 You're change certainly gets the job done. However, the code you were touching is actually duplicated code. Bootstrap requires to manually initialize popovers. When we dynamically add content to the page, we have to reinitialize this. I outsourced this behavior to a new function in app/assets/javascripts/bootstrap_popovers.js which is called from the respective places, so that we don't have the same code all over the place.

If you are fine with this, please make sure to test that popovers work everywhere, e.g. test popovers at some places, but especially in places where content is loaded dynamically, e.g. when you add a new chapter and a modal opens for that operation that has some popovers (helptexts) in it.

[Frodo161]

I didn't see anything in the code (except the two missing lines you already added).

In my local MaMpf environment I tested some popovers (chapters, sections, lessons, comments and some more) and everything worked.