feat: make formatMessage take in ReactElement

[longlho]

Allow using formatMessage with ReactElement imperatively, e.g:

formatMessage('hello {world}', {world: <b>world</b>)
// returns ['hello ', <b>world</b>]

New signature will be:

formatMessage(msg: string, values: Record<string, string | number | null | undefined | React.ReactNode>): string[] | React.ReactNodeArray

Use case:

• Right now the only way to format rich text is to use FormattedMessage, this brings feature-parity to the imperative version formatMessage as well.
• formatMessage is also faster and doesn't create extra React Node.
• Also remove the need to regen UUID for every rich text token in FormattedMessage, which improves perf as well
  Before:

100 x <FormattedMessage> with placeholder x 76.83 ops/sec ±9.83% (69 runs sampled)
100 x <FormattedMessage> with placeholder in AST form x 206 ops/sec ±1.12% (79 runs sampled)
100 x <FormattedMessage> with placeholder, cached x 573 ops/sec ±1.07% (84 runs sampled)
100 x <FormattedMessage> with placeholder, cached in AST form x 392 ops/sec ±4.28% (82 runs sampled)

After:

100 x <FormattedMessage> with placeholder x 85.51 ops/sec ±3.66% (66 runs sampled)
100 x <FormattedMessage> with placeholder in AST form x 210 ops/sec ±2.27% (76 runs sampled)
100 x <FormattedMessage> with placeholder, cached x 619 ops/sec ±2.00% (87 runs sampled)
100 x <FormattedMessage> with placeholder, cached in AST form x 426 ops/sec ±1.61% (84 runs sampled)

[redonkulus]

What’s the use case for this?

[longlho]

@redonkulus I updated the desc