[greasemonkey]: add generics to GM.getValue(string) overload to avoid breaking change at 4.0.4

[trim21]

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Neither, this fix a breaking change added at 4.0.4

previous PR #61907 says due to no-unnecessary-generics rule that GM.getValue without default value should be GM.getValue(name: string): Promise<GM.Value | undefined>, but this will break old working code:

  type Type = 'enum 1' | 'enum 2' | 'enum 3' | ...;
  let v: Type | undefined = await GM.getValue<Type>(key);
  if (!v) {
    init_or_set_v_value()
  }

it raise Type 'Value | undefined' is not assignable to type 'Type | undefined'.   Type 'string' is not assignable to type 'Type | undefined'.

or

  let v = await GM.getValue<Type>(key);

raise error TS2554: Expected 2 arguments, but got 1.

User can call it like GM.getValue(key) as Type | undefined but it still a breaking change when upgrading @types/greasemonkey from 4.0.3 to 4.0.4.

[typescript-bot]

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[typescript-bot]

🔔 @kotas @nikolay-borzov — please review this PR in the next few days. Be sure to explicitly select Approve or Request Changes in the GitHub UI so I know what's going on.

[typescript-bot]

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[nikolay-borzov]

Sorry for bringing breaking changes. But what's stopping you from updating you code?
I believe 4.0.4 update improves types definitions. Using generic for casting types is wrong.

[trim21]

Sorry for bringing breaking changes. But what's stopping you from updating you code? I believe 4.0.4 update improves types definitions. Using generic for casting types is wrong.

Nothing, this PR just prevent breaking change.

And in fact, the other overload getValue<TValue = GM.Value>(name: string, defaultValue: TValue): Promise<TValue> is still using generic as return value type casting for real return type Promise<GM.Value | TValue>.

[typescript-bot]

Re-ping @kotas, @nikolay-borzov:

This PR has been out for over a week, yet I haven't seen any reviews.

Could someone please give it some attention? Thanks!

[nikolay-borzov]

I fail to understand why this PR exists providing:

1. We cannot change MAJOR version of the package
2. BREAKING CHANGE can be easily fixed
3. This PR rollbacks to the wrong type definitions