feat(useExplicitFunctionReturnType): support typed function expressions

[kaykdm]

Summary

related: #2017

This PR introduces the ability to detect typed function expressions in the useExplicitFunctionReturnType rule.

todos:

• A function with a type assertion using as or <>

const asTyped = (() => '') as () => string;
const castTyped = <() => string>(() => '');

• A variable declarator with a type annotation

type FuncType = () => string;
const arrowFn: FuncType = () => 'test';

• A function as a default parameter with a type annotation

type CallBack = () => void;
const f = (gotcha: CallBack = () => { }): void => { };

• A class property with a type annotation

type MethodType = () => void;
  class App {
     private method: MethodType = () => { };
}

• A function as a property or a nested property of a typed object

const x: Foo = { prop: () => {} }
const x = { prop: () => {} } as Foo
const x = <Foo>{ prop: () => {} }
const x: Foo = { bar: { prop: () => {} } }

[codspeed-hq]

CodSpeed Performance Report

Merging #4174 will degrade performances by 33.19%

_{Comparing kaykdm:support-typed-function-expressions (acf69c8) with main (055b0db)}

Summary

❌ 1 regressions
✅ 104 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	kaykdm:support-typed-function-expressions	Change
❌	big5-added_15586211152145260264.json[uncached]	547 µs	818.8 µs	-33.19%

[Conaclos]

You made it! Thanks for your amazing contribution 💗