Allow overriding default schema in from and rpc

[osaxma]

Feature request

This request was originally filed at supabase/supabase-flutter#206

Is your feature request related to a problem? Please describe.

Currently it's only possible to use a single schema -- i.e. the one passed to the client upon instantiation.

Describe the solution you'd like

In some cases, I would like to run a query or invoke an rpc on a different schema than the one given to the client initially such as:

const client = PostgrestClient('url', {schema: 'public'});

// some where else in the app
const { data, error } = await supabase.from('table_name', 'schema_name' ).select()
// or
const { data, error } = await supabase.rpc('function_name', 'another_schema_name')

In both cases, if no schema is given, then the default schema from the client is used.

Describe alternatives you've considered

Creating multiple clients (one per schema) seems like the only option but it'd be much easier and cleaner to use the same client.

[soedirgo]

Does this look like what you want? #280

[osaxma]

@soedirgo yeah I believe the same with different proposed solution(s) ... I'll close this and follow up there..

Thanks 🙏