Updates the UI to show a "more visual" representation, making use of the
newly-created "advanced" radio button group input.
Extracts the inline form into `TemplateSelectForm` for easier reuse/
adaptability for upcoming project creation wizard.
Makes `TemplateSelectComponent` and `SourceProjectSelectComponent`
implementations consistent. `TemplateAutocompleter` is unlikely to be
reused by other components at present.
Updates the form visuals according to new wireframes: the Project create
form now only includes required (built-in and custom) fields, along with
the "Subproject of" field.
In detail:
* Introduces `Projects::NewComponent` and `TemplateSelectComponent`.
* Adds, extends necessary Primer forms with basic specs.
* Adds `ProjectsController#create` action, routes and permissions.
* Adds `highlight-when-value-selected` Stimulus controller.
* Updates project feature specs for new form, including rewriting some
expectations that were reliant on `data-qa-name` attribute that Primer
form components do not render by default.
* Removes now obsolete Project Status administation feature spec.
Henriette Darge