Give data version the new format <major>.<minor>, so that
the version can be incremented with the introduction of new
features without bumping the major version.
Add support for loading instrumentation JSON queries of unknown
data versions without error.
Issue: #27833
Add a `CUSTOM_CONTENT` argument to `cmake_instrumentation()` for collecting
custom content from configure time.
Snippet files include a reference to a JSON file containing any `CUSTOM_CONTENT`
that was added by this command.
Fixes: #26703
Run the `clang-format.bash` script to update all our C and C++ code to a
new style defined by `.clang-format`, now with "east const" enforcement.
Use `clang-format` version 18.
* If you reached this commit for a line in `git blame`, re-run the blame
operation starting at the parent of this commit to see older history
for the content.
* See the parent commit for instructions to rebase a change across this
style transition commit.
Issue: #26123