Author and committers approvals are split in EE
This commit provides backports for those changes

This reverts commit 886f00bc.

Adds `# frozen_string_literal: true` to spec/models ruby files

Allow incomplete commit records to load their full data from gitaly.

Commits can be based on a Hash of data retrieved from PostgreSQL, and
this data can be intentionally incomplete in order to save space.

A new method #gitaly? has been added to Gitlab::Git::Commit, which
returns true if the underlying data source of the Commit is a
Gitaly::GitCommit.

CommitCollection now has a method #enrich which replaces non-gitaly
commits in place with commits from gitaly.

CommitCollection#without_merge_commits has been updated to call this
method, as in order to determine a merge commit we need to have parent
data.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/58805

Revert "Merge branch '58805-allow-incomplete-commit-data-to-be-fetched-from-collection' into 'master'"

This reverts merge request !26144

Allow incomplete commit records to load their full data from gitaly.

Commits can be based on a Hash of data retrieved from PostgreSQL, and
this data can be intentionally incomplete in order to save space.

A new method #gitaly? has been added to Gitlab::Git::Commit, which
returns true if the underlying data source of the Commit is a
Gitaly::GitCommit.

CommitCollection now has a method #enrich which replaces non-gitaly
commits in place with commits from gitaly.

CommitCollection#without_merge_commits has been updated to call this
method, as in order to determine a merge commit we need to have parent
data.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/58805

This backports the changes made in EE to fix merge request approvers
from https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/9574.

These are used by the EE-only approvers feature

This adds an optimised way of getting the latest pipeline status for a
list of Commit objects (or just a single one).