message search support for non-english user

[xylonx]

Description:

As coded below, I find now the message analyzer is 'english' only.

synapse/synapse/storage/databases/main/search.py

Line 86 in e9a4343

VALUES (?,?,?,to_tsvector('english', ?),?,?)

synapse/synapse/storage/databases/main/search.py

Line 470 in e9a4343

WHERE vector @@ websearch_to_tsquery('english', ?)

But there are also many non-english users like me in matrix community.

Is it possible to make the analyzer configurable to split non-english sentences for better searching experience or pass the search requests to third-party full-text search engine like elasticsearch?

[clokep]

I think this is essentially a duplicate of #10559 and/or #901.

[DMRobertson]

#14608 has some more links and exploration of elasticsearch.