Missing header files from external repositories during analysis

[furtib]

Describe the bug
On targets with implementation_deps external dependencies using strip_include_prefix, header files are not found correctly.

Versions
Versions of CodeChecker, bazel and this repo. You can get version info via:

• CodeChecker 6.26.1
• bazel 6.5.0
• 2f291d3

To Reproduce
Checkout this branch: https://github.com/Szelethus/codechecker_bazel/tree/test_system_headers

Expected behaviour
External headers to be found.

Additional context
This is an edge case of #120

[furtib]

Does not work in per_file rule.