feat(es/parser): support type-only import/export specifiers

[g-plane]

Ref: microsoft/TypeScript#45998

This PR allows:

import { type foo } from 'mod'
import { type foo as bar } from 'mod'

but rejects:

import type { type foo } from 'mod'

[dsherret]

I think we should still parse this scenario even though it is invalid. It would be useful in dprint-plugin-typescript for example to parse this then convert import type { type something} from 'mod' to import type { something } from "mod";. Thoughts? (by the way, nice PR)

[g-plane]

I think dprint is a formatter, and it shouldn't accept code with invalid syntax.

[dsherret]

In the TS parser implementation they always parse this: https://github.com/microsoft/TypeScript/pull/45998/files#diff-12a6724be007eb1a19d80018c7a63bbc73525ca793a9b3e5da49a4e86bbf457c

That allows the language service and other code analysis to understand this code even though it might not be correct.

Then in the checker.ts code that's where they check if this is allowed: https://github.com/microsoft/TypeScript/pull/45998/files#diff-d9ab6589e714c71e657f601cf30ff51dfc607fc98419bf72e04f6b0fa92cc4b8R43439-R43450

Is there any harm in always parsing this even when it is a type-only import/export? I also think parsing this would align more with swc's type checker.

[g-plane]

I prefer that this would be syntax errors, but I'm OK to treat it as valid syntax, because this isn't a huge change.

The biggest annoying problem is that once I change the code, rustc will cost very very long time.

[kdy1]

It can be syntax error and can be valid ast in same time, and I think it's the right direction to go.
emit_err can be used for such purpose.

[kdy1]

Thanks!
Parser changes LGTM, but I found some small issues about the role of crates.

[kdy1]

It can be syntax error and can be valid ast in same time, and I think it's the right direction to go.
emit_err can be used for such purpose.

[g-plane]

I've used emit_err in ecmascript/parser/src/parser/stmt/module_item.rs, but I can't hide the review conversation above.

[kdy1]

LGTM. Thanks a lot!