[legacy-framework] Fix resolver.authorize( doesn't work as type guard (with great effort)

[hasparus]

Closes: blitz-js/legacy-framework#411

What are the changes and their implications?

Functions in resolver.pipe can now modify the type of Ctx.

Checklist

• Changes covered by tests (tests added if needed) — There's no way to test this automatically (yet?)
• PR submitted to blitzjs.com for any user facing changes — not needed

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I left overloads higher than n commented, because I want to discuss it.

I highly doubt anybody is going to use more than 12 function inside pipe, and you can always compose functions inside.
Each overload is slightly affecting user's TypeScript performance (as I'm too lazy to write more overloads, I'm also too lazy to back this claim with benchmarks, so you'll have to trust me :P)

[hasparus]

I declared the type of resolver.authorize separately, because it was getting pretty complex, and while "types first, implementation later, functions as interfaces" is probably the most tiring way to write TS types, it results in the shortest error messages and tooltips

[andrekovac]

@hasparus Very interesting comment.

Where can I read more about the "types first, implementation later, functions as interfaces" philosophy?

I understand "types first, implementation later". But what exactly does "functions as interfaces" mean in this context? How does this fit together with the fact that PipeFn is also a function, but you defined it as type alias and not as interface?