Errors in application settings panel shows wrong panel

See merge request gitlab-org/gitlab-ce!25434

Fixed failing GraphQL file import

Closes #63527

See merge request gitlab-org/gitlab-ce!29900

This commits adds support for metrics dashboards
for embedding. If the flag 'embedded' is provided
to the environments/id/metrics_dashboard endpoint,
the response will be suitable for embedding in
issues or other content.

This is a precursor for support for embedding
metrics in GFM.

Render last commit widget with Vue

Closes #62766

See merge request gitlab-org/gitlab-ce!29419

Rename graphql files to match frontend docs

See merge request gitlab-org/gitlab-ce!29856

Remove import columns from projects table

See merge request gitlab-org/gitlab-ce!29863

This adds a `markdown_field` to our types.

Using this helper will render a model's markdown field using the
existing `MarkupHelper` with the context of the GraphQL query
available to the helper.

Having the context available to the helper is needed for redacting
links to resources that the current user is not allowed to see.

Because rendering the HTML can cause queries, the complexity of a
these fields is raised by 5 above the default.

The markdown field helper can be used as follows:

      ```
      markdown_field :note_html, null: false
      ```

This would generate a field that will render the markdown field `note`
of the model. This could be overridden by adding the `method:`
argument. Passing a symbol for the method name:

      ```
      markdown_field :body_html, null: false, method: :note
      ```

It will have this description by default:

> The GitLab Flavored Markdown rendering of `note`

This could be overridden by passing a `description:` argument.

The type of a `markdown_field` is always `GraphQL::STRING_TYPE`.

In https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/21497, we
migrated all project import data into a separate table,
`project_import_data`.  In addition, we also added:

```
ignore_column :import_status, :import_jid, :import_error
```

In https://gitlab.com/gitlab-com/gl-infra/production/issues/908, we
observed some of these `import_error` columns consumed megabytes of
error backtraces and caused slow loading of projects whenever a `SELECT
* from projects` query loaded the row into memory.

Since we have long migrated away from these columns, we can now drop
these columns entirely.

Updated users API documentation
Moved API level changes to the service level