pw_build/cmake: Enforce full path in CMake library names
pw_build/cmake: Enforce full path in CMake library names

Instead of only enforcing the parent directory to be in the CMake
library name, pw_add_module_library is updated to enforce that
the entire relative to PW root directory path is in the library
name in a dot separated format.

Change-Id: I29f3fa499474a53ff29a04ed2f353d560edd1451
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/94540
Pigweed-Auto-Submit: Ewout van Bekkum <638f134dbc68778d6b859fb04a64baea2b00b021@google.com>
Reviewed-by: Keir Mierle <69344103cc60b36d6e1fbdc31ce6504b2286c646@google.com>
Commit-Queue: Auto-Submit <14637eda5603879df170705285bf30f5996692f0@pigweed.google.com.iam.gserviceaccount.com>

google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed