Pasting a list into another list (fix list-style attr)

[pomek]

#7959 # Suggested merge commit message (convention)

Fix (list): List styles will be inherited correctly when pasting a list into another list. Closes #8160.

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Additional information

I know, I used the best solution for detecting that content comes from pasting… How could we improve that?

[jodator]

@pomek I thought it would require extracting the if() to separate method but it turned out that it has many drawbacks: 00610fd.

• There was missing wasFixed = true and the condition was causing infinite fix-loops as the check caught also cases of the same list types.
• The logic was slightly different from shouldInheritListType() and the if( prevSibling && was duplicated from that function - so I've inlined those checks in new function.
• Then it was just moving the method around.

[jodator]

Additionally, I've moved the check from the fixListStyleAttributeOnListItemElements() so the functions will not be re-created on every fixListStyleAttributeOnListItemElements() call.

[jodator]

LGTM ;)