This fix makes some fundamental changes to the way symbols are rescued:
* The new symbol library file format is used when rescuing symbols defined
in the symbol library table.
* The original library nickname is appended to the symbol name rather than
the rescue library nickname when rescuing symbol defined in the symbol
library table.
* Escaping strings has been removed from legacy library rescues since the
legacy library file format never supported it.
Fixes https://gitlab.com/kicad/code/kicad/-/issues/12525
Fixes https://gitlab.com/kicad/code/kicad/-/issues/12624
The original decision to escape the legacy symbol library names results
in them being escaped every time they are opened which cause the curly
braces '}' from the original escaping to be escaped on subsequent
openings. This resulted in the symbol library names in the rescue
library not matching the library ID in the schematic.
This fix is likely to have other corner case bugs given the potential
for escaped characters in legacy symbol libraries. Given that we now
have escaped rescue libraries in play, removing the escaping will only
result in more issues so we will have to fix the corner cases as we go.
Fixes https://gitlab.com/kicad/code/kicad/-/issues/11563