Rework type guards in Radashi

[aleclarson]

There are libraries like @sindresorhus/is out there that are more widely used, which are therefore more battle-tested/robust and (perhaps most importantly) more comprehensive.

I suggest copying my code from https://github.com/alloc/is/blob/master/src/is.ts (which is written to be tree-shakeable and not rely on NodeJS types anywhere). Then we can update its implementation to align with @sindresorhus/is to achieve the same robustness without the baggage.

Related issues

• isNumber(NaN) sodiray/radash#405

[nnmrts]

For return types radashi could also profit from https://github.com/sindresorhus/type-fest.

[aleclarson]

Appreciate the suggestion! 👍 We might already have types from there even!