GetTreeEntries doesn't support pagination
Related issues:
The frontend uses GraphQL to load the files in the repository tree (https://gitlab.com/gitlab-org/gitlab/blob/78e71f16c035e1c68350a0a912d8d3bfdc35d3cc/app/graphql/queries/repository/files.query.graphql, https://gitlab.com/gitlab-org/gitlab/blob/dcff57eedba4ac89f3a2de6559b6a742f614427c/app/assets/javascripts/repository/components/tree_content.vue#L77), and it attempts to do this by loading 100 entries at a time up to 10 pages.
The problem, however, is that we load the entire tree (and attempt to flatten subdirectory paths). The GraphQL endpoint takes most of this output and only takes 100 entries.
It seems to me the GraphQL endpoint and the RPC should work together: there should be a offset and limit parameter in GetTreeEntries.