* Better git usage in donate-cpu.py to reduce bandwidth and disk usage
Main changes:
* Bump client version
* Move try+retry logic to function try_retry to reduce duplication
* Use exponential backoff for try_retry
* git clone with --depth=1 to reduce bandwidth and disk use
* Use multiple worktree to work with multiple versions, instead of back-and-forth checkouts
* donate-cpu.py fixes for review comments and automated check failures
* Move compile_cppcheck within (if ver == 'main) branch to avoid duplicate compile_cppcheck+compile_version cals
* Use classic format syntax for python 3.5 compatibility
* Fix undefined CalledProcessError detected by pylint
* donate-cpu.py code changes following code review
* Migration existing "cppcheck" directory if available instead of "git clone"
* Logging message tweaks
* Use subprocess' cwd parameter instead of os.chdir() to avoid risk around changing and not restoring the working directory
* Update tools/test-my-pr.py to account for donate_cpu_lib changes
* donate-cpu.py: ensure correct workspace locations with relative --work-path
This adds a timeout of 60 minutes for the Cppcheck analysis.
Timed out results do not count as crash but they are uploaded and
marked with "TO!" in the list of the latest results. No "diff" is
generated for timed out results so they do not add wrong entries to
the "Diff report".
In test-my-pr.py the timed out results are listed separately just like
the crashes.
donate-cpu-server.py: Add timeout report
Previously, calling test-my-pr with a relative work-path resulted in a
crash when trying to create the result file (due to the change of
current working directory).