Is your feature request related to a problem? Please describe.

When creating a plugin I cannot populate JPATH_ROOT/layouts/plugins/myplugin/... by using a tag in the manifest like I do with media files.

Would prefer not to achieve this using the scriptfile tag.

Describe the solution you'd like

In installer.php add function parseLayouts(\SimpleXMLElement $element, $cid = 0) which will work in the same manner as parseMedia(...).

Calls to this function will then need to be added to the parseOptionalTags() function in each of the relevant adapters.

Additional context

Using layouts/plugins in this way is consistent with how com_templates manages layout overrides.