cmake: Add per-language link flags for all target types

Previously, `CMAKE_<LANG>_LINK_FLAGS` was an undocumented variable used
for linking executables only. Re-spell that variable mirroring the
existing spellings for shared and module libraries, and add policy
CMP0210 to preserve compatibility.

Then, repurpose `CMAKE_<LANG>_LINK_FLAGS` to provide a variable to be
used for per-language link flags for all target types, along with a
per-configuration variant. These are added to the `<LINK_FLAGS>` rule
placeholder in the generators.

Fixes: #21934
Relates: #25620

Co-authored-by: Brad King <brad.king@kitware.com>