feat: filter top-level resource with embed filter

This is enabled by adding `!inner` to the embedded resource

/projects?select=*,clients!inner(*)&clients.id=eq.12

This behaviour can be enabled by default with the config option

db-embed-default-join='inner'

Which saves the need for specifying `!inner` on every request.
If this is enabled, the previous behavior can be restored
per request by specifying `!left`  on the embedded resource.

/projects?select=*,clients!left(*)&clients.id=eq.12`

Tested on M20/02M/M2M relationships, views, RPC.

test/io-tests/configs/expected/boolean-string.config

@@ -12,6 +12,7 @@ db-schemas = "required"
 db-config = "false"
 db-tx-end = "commit"
 db-uri = "required"
+db-embed-default-join = "left"
 jwt-aud = ""
 jwt-role-claim-key = ".\"role\""
 jwt-secret = ""