Coherent update from 'best-fit' to 'best fit'

[valdoryu]

Hi, this PR aims to solve a build issue that occurs when you use vue-i18n 9.0.0 with Vite & Vue 3
Here is the error:

vue-tsc --noEmit && vite build
node_modules/@intlify/core-base/dist/core-base.d.ts:526:26 - error TS2430: Interface 'SpecificDateTimeFormatOptions' incorrectly extends interface 'DateTimeFormatOptions'.
  Types of property 'localeMatcher' are incompatible.
    Type '"lookup" | "best-fit" | undefined' is not assignable to type '"best fit" | "lookup" | undefined'.
      Type '"best-fit"' is not assignable to type '"best fit" | "lookup" | undefined'.

526 export declare interface SpecificDateTimeFormatOptions extends Intl.DateTimeFormatOptions {

On vue-i18n, best-fit was renamed to best-fit in 8.X but the change has not been propagated to core-base

Here is the original PR:
kazupon/vue-i18n#1118

[kazupon]

Thank you for your contribution!
This PR resolve #390 too.

Thanks!

[kazupon]

We will be released with v9.1!
Please wait!

[valdoryu]

I will, thank you