The header checks described in
CDRIVER-2797 are repeated throughout the codebase.
We should consider refactoring them into three files
mongoc-header-check.h, consisting of:
bson-header-check.h, consisting of:
And common-header-check.h, consisting of:
We can verify with an Evergreen task that each header (except bson.h and mongoc.h) includes one of these checks directly after the license. We could also use the same check to verify that each file has a license.