Add Meilisearch to tutor core

[pomegranited]

Meilisearch must be deployed and enabled to support Libraries v2, and course content searching in the Authoring MFE.
Additionally, there's a Meilisearch engine for courseware and course discovery content search.

Currently, meilisearch is in an optional plugin, but we want it to be installed and enabled in Tutor by default.

Part of: openedx/frontend-app-authoring#1334

• Integrate this plugin into Tutor core
• Enable it by default
• Allow connections to remote instances
• Include the k8s support provided by the plugin's patches
• Consider providing SEARCH_ENGINE = "search.meilisearch.MeilisearchEngine" to the LMS / CMS settings to use feat: add Meilisearch-compatible search engine edx-search#162
• Remove the meilisearch plugin from the Tutor plugins index: https://github.com/search?q=repo%3Aoverhangio%2Ftpi%20meilisearch&type=code -- Meilisearch is now in tutor master, but not yet in nightly, so this plugin is still useful there.

[regisb]

Here's the PR: overhangio/tutor#1141