fix(types): export type utils for ssr use

[avallete]

What kind of change does this PR introduce?

2.50.4 introduced a breaking change into SupabaseClient types templating parameter which caused an issue when upgrading and using @supabase/ssr since it re-use the same typing logic for it's own createXXXClient functions.

This is an attempt to:

1. Add a smoking test within supabase-js to be notified of this kind of types breakage when they occurs before releasing.
2. Add new utils so we can move some of the typing logic from @supabase/ssr to @supabase/supabase-js

BREAKING CHANGES:

• SupabaseClient now have options as second parameter instead of SchemaName which will require some migration if using the SupabaseClient type directly:

// from
type PublicClient = SupabaseClient<Database, 'public'>
// to
type PublicClient = SupabaseClient<Database, { PostgrestVersion: '12' | '13' }, 'public'>
// or if your introspected Database has the `__InternalSupabase` schema:
type PublicClient = SupabaseClient<Database, Database['__InternalSupabase'], 'public'>

Why this change ?

It allows the typing of the client to prepare an takes into account different postgrest version, and accounting for the slight differences in behavior between the two versions at typing level.

[coveralls]

Pull Request Test Coverage Report for Build 16217719297

Details

• 2 of 2 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 81.14%

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Totals
Change from base Build 16197271777:	0.0%
Covered Lines:	118
Relevant Lines:	135

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💛 - Coveralls

[avallete]

introduce basics typing tests for the @supabase/ssr context. Since it depends of supabase-js as peer deps, it'll help detect uncaught breaking change that would break compatibility between ssr and supabase-js previous verison.