Merge branch 'ps/object-store' into ps/object-store-midx

* ps/object-store: odb: rename `read_object_with_reference()` odb: rename `pretend_object_file()` odb: rename `has_object()` odb: rename `repo_read_object_file()` odb: rename `oid_object_info()` odb: trivial refactorings to get rid of `the_repository` odb: get rid of `the_repository` when handling submodule sources odb: get rid of `the_repository` when handling the primary source odb: get rid of `the_repository` in `for_each()` functions odb: get rid of `the_repository` when handling alternates odb: get rid of `the_repository` in `odb_mkstemp()` odb: get rid of `the_repository` in `assert_oid_type()` odb: get rid of `the_repository` in `find_odb()` odb: introduce parent pointers object-store: rename files to "odb.{c,h}" object-store: rename `object_directory` to `odb_source` object-store: rename `raw_object_store` to `object_database`