feat(resource-full-text-search): add text vector columns and GiST indexes for notion

[fontanierh]

This PR adds:

• a sql query in connectors db.ts to enable the unaccent extension if not yet enabled (tried to switch it on in prod, worked fine)
• a titleSearchVector TSVECTOR column on notion_pages and notion_databases
• a GiST index on the titleSearchVector column for notion_pages and notion_databases
• a trigger to update titleSearchVector whenever the title is updated on either a notion_pages or notion_databases row
• a migration script to populate titleSearchVector on existing notion_pages and notion_databases rows

I went with GiST instead of GIN (means faster to insert/build, but slower to search). Rationale is that the dataset is not static, and will be more write-heavy than read-heavy. Wonder if that's the write choice ? WDYT @lasryaric @spolu ?

[spolu]

I presume we can easily switch between GIST and GIN in the future anyway?

[fontanierh]

I presume we can easily switch between GIST and GIN in the future anyway?

yes I believe it's a one line change + running db sync @spolu

[spolu]

What's the status here?

[fontanierh]

What's the status here?

I'm merging it