Fix #26402: Formatting lost when special character is copied and pasted

[mafaldarpdias]

Resolves: #26402

Copying and pasting a musical symbol with a modified size in a system text object caused the size to reset. This happened because the cursor used during insertion was from the paste location rather than the copied element. Additionally, the format was not properly stored in the edit text object (ed), so when TextBase::insertSym() was called, it lacked the correct formatting.
I fixed this by ensuring the correct cursor was used for insertion and explicitly setting the format in the edit text object before passing it to TextBase::insertSym() during TextBase::paste(), preserving the symbol’s modified size.

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[mathesoncalum]

Cool, this all looks sensible to me - thanks very much!