Analyze and resolve issues caused by `strict_warnings` toolchain feature from `score_bazel_cpp_toolchains`

The `score_bazel_cpp_toolchains` toolchain has introduced a "strict_warnings" toolchain feature, which enables a very "strict" set of compile warnings.

Many Bazel targets in this repo explicitly set the "strict_warnings" feature, commonly in combination with "treat_warnings_as_errors" (see for example: https://github.com/eclipse-score/baselibs/blob/v0.2.3/score/bitmanipulation/BUILD#L23).

As a result, most targets either fail to compile or emit a large number of compiler warnings. Currently, this is being worked around by explicitly disabling the `strict_warnings` feature in `.bazelrc` (https://github.com/eclipse-score/baselibs/blob/v0.2.3/.bazelrc#L26).

Note: Users of the baselibs module may also need a similar workaround.

**Task:**
- Analyze which compiler warnings in the `strict_warnings` list should be removed if they are not beneficial.
- Identify which warnings/issues should instead be corrected in the baselibs source code.
- Propose changes to either the toolchain's `strict_warnings` feature or to the code in `baselibs` as appropriate.