[Course Search] Initial Integration of Studio Search Backend

[bradenmacdonald]

"As a course author, I want to be able to search course content in Studio"

For this ticket, get the prototype openedx/openedx-platform#34310 to a mergeable state by adding the following missing pieces:

1. The ability to turn the feature off (e.g. when Meilisearch is not installed). It should be off by default, as the current version does not enforce permissions and most installations do not have Meilisearch.
2. Only allow users with Studio access to use the StudioSearchView REST API (more detailed permissions will be added in a future story).
3. Add the course/library name to the index.
4. Add content location (breadcrumbs) to search index documents (name of each parent block, if applicable - e.g. Course > Section > Subsection > Unit). Handle cases where the block is a child of a library content block by including the LCB in the breadcrumbs too?
5. Add some tests.
6. Include an ADR for Meilisearch and what the plan is after it has been evaluated using this project.

Other functionality (updates to the index, permissions) will come in other tickets - see the milestone for links to them.