Add #environments_cluster_path which will always return nil in CE

See merge request gitlab-org/gitlab-ce!32527

This commit adds pipeline.type key to PipelineEntity.
This key will be used in MR widget in the next iteration.

This method will be overridden in EE

Instead of highlighting all lines when not all of them
are needed, only highlight from the beginning up to
the specified limit.

The `BlobPresenter#highlight` method has been updated
to support `to` param. This param will be used to limit
the content to be highlighted.

The virtus project has been discontinued:

https://github.com/solnic/virtus/commit/a6f896984

- expand upwards
- expand downwards
- expand all

in both inline and parallel views

This reverts merge request !31361

Support selective highlighting of lines

See merge request gitlab-org/gitlab-ce!31361

Instead of highlighting all lines when not all of them are
needed, only highlight specific lines.

The `BlobPresenter#highlight` method has been updated to
support `since` and `to` params. These params will be used to
limit the content to be highlighted.

Modify `Gitlab::Highlight` to support `since` param which will
then be used to determine the starting line number.

This commit changes how we eager-load projects, routes, and namespaces
required by the deploy keys endpoint, getting a 10x improvement in my
local testing.

The endpoint still doesn't scale in-general, but going from ~13 seconds
to dump a 63K result to generating the same thing in ~1.6 seconds seems
like a good improvement to me.