[bugfix] change function overload order in Form typescript define

[TomIsion]

When I use with Form.create()() and this.props.form.validateFields with async/await in typescript:

this.prop.form.validateFields(async (errors, values) {
  // code here
  // writing sth need to block
  const a = await getInfo();
})

tslint always tell me: [ts] Parameter 'errors' implicitly has an 'any' type.

In typescript, async/await callback will conform these after typescript overload define:

validateFields(options: Object): void;
validateFields(callback: ValidateCallback): void;

The async/await func should use callback define firstly. Just like the above define in Form.d.ts:

validateFields(fieldNames: string[], callback: ValidateCallback): void;
validateFields(fieldNames: string[], options: Object): void;

So I change the order of the function overload define.

[codecov]

Codecov Report

Merging #12538 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #12538   +/-   ##
=======================================
  Coverage   92.33%   92.33%           
=======================================
  Files         211      211           
  Lines        5542     5542           
  Branches     1599     1599           
=======================================
  Hits         5117     5117           
- Misses        419      421    +2     
+ Partials        6        4    -2

Impacted Files	Coverage Δ
components/form/Form.tsx	95% <ø> (ø)	⬆️
components/transfer/index.tsx	87.91% <0%> (ø)	⬆️
components/time-picker/index.tsx	81.96% <0%> (ø)	⬆️

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