new `Move to file` refactoring should avoid name collisions

[zardoy]

Suggestion

I tested it in insiders + nightly in the following way:

export const getData = () => ({
 foo: true
})
const data = getData()

// target file
const getData = () => ({
 bar: false
})

const data = getData()

After moving

Actual:

const getData = () => ({
 bar: false
})

const data = getData()
export const getData = () => ({
 foo: true
})

Expected:

const getData = () => ({
 bar: false
})

const data = getData()
export const getData2 = () => ({
 foo: true
})
// original file:
import { getData2 as getData } from "./file2"

const data = getData()

I can even see the test that explicitly captures this case (added by navya9singh in #53542):
https://github.com/microsoft/TypeScript/blob/ea6441d3d77963b1c692c8aca023a822e039dc67/tests/cases/fourslash/moveToFile_unresolvedImport.ts that would obviously break real world code after. I would expect a to be named as a2 after moving I guess?

THe real problem is that sometimes you just can't tell wether specific file has confliciting top-level identifiers and you have to rename these symbols either in source or target file, but user also could rename these symbols after the refactoring instead (e.g. getData2 to something else). Introduce variable / function just use one function call to avoid name collisions:

https://github.com/microsoft/TypeScript/blob/7c378dbab3ab590835c3adbd260f37c97fba1111/src/services/refactors/extractSymbol.ts#LL1042C33-L1042C39

The same thing also applies for names coming from imports:

// source file
import { groupBy } from 'lodash'

groupBy([], (val) => val)

// target file
import { groupBy } from 'lodash'

groupBy([], (val) => val)

After refactor:

// actual
import { groupBy } from 'lodash'
import { groupBy } from 'rambda'

groupBy([], (val) => val)
groupBy((val) => val, [])

// expected
import { groupBy } from 'lodash'
import { groupBy as groupBy2 } from 'rambda'

groupBy([], (val) => val)
groupBy2((val) => val, [])

This code is not broken :shrug :.

This is painful when you have huge project that in process of migration from lodash to rambda api.

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