cmake: scripts: supporting gen_relocate_app feature in windows

Fixes: #28847

This commit fixes two places that was causing gen_relocate_app to fail
in windows.

gen_relocate_app.py now splits only on first `:` in
`<MEM_REGION>:<file>`.

Windows contains `:` in path, thus only first `:` is valid for splitting
mem region and file path.

Second part of the issue is fixed in CMake where `'` was used for
quoting of command arguments.
This causes a file not found on Windows because the final `'` would be
treated as part of the filename. Similar the first `'` would be treated
as path of the mem region name.

This is fixed by using `"` for quoting, which works correctly on all
platforms.

gen_relocate_app.py:403: UserWarning: File: .../kernel/sem.c' Not found
Note the stray `'`                                         ^^^

Signed-off-by: Torsten Rasmussen <Torsten.Rasmussen@nordicsemi.no>