This was being masked by the statement cache because only one author was used
per issue in the test..

Also adds support for an Rspec matcher `exceed_all_query_limit`.

In CE, every `Issue` entity is also a `ProjectEntity`, which calls
`entity&.project.try(:id)` to show the project ID. In an API
request with 100 issues, this would hit the Rails statement cache 100 times
for the same project and cause unnecessary overhead as related models would
also be loaded.

In EE, we call `Issue#supports_weight?` for each issue, which then calls
`project&.feature_available?(:issue_weights)`. If the project is not
preloaded, this incurs additional overhead, as each individual Project
object has to be queried. This can lead to a significant performance hit.
In loading the CE project with 100 issues, this contributed to at least 22%
of the load time.

See https://gitlab.com/gitlab-org/gitlab-ce/issues/47031 for why testing this
is a bit tricky.

Resolve "API naming for issue scope"

Closes #44799

See merge request gitlab-org/gitlab-ce!18935

Deprecate corresponding dash versions created-by-me and assigned-to-me

This ensures that we have more visibility in the number of SQL queries
that are executed in web requests. The current threshold is hardcoded to
100 as we will rarely (maybe once or twice) change it.

In production and development we use Sentry if enabled, in the test
environment we raise an error. This feature is also only enabled in
production/staging when running on GitLab.com as it's not very useful to
other users.