Introduces a new Bazel test that allows us to inspect
what source-files contribute to a given bundled file
and how much bytes they contribute to the bundle size.
Additionally the size-tracking rule groups the size
data by directories. This allows us to compare size
changes in the scope of directories. e.g. a lot of
files in a directory could increase slightly in size, but
in the directory scope the size change could be significant
and needs to be reported by the test target.
Resolves FW-1278
PR Close#30070
Paul Gschwendtner