feat: add prefix to useId hook

[mihkeleidast]

Context

• If some other dependency has a similar implementation of useId that only returns an incremented number, these IDs can conflict.
• Number-only ID-s are hard to read (mostly personal preference)

Analysis

This will solve a potential conflict where another third-party dependency has a similar implementation of a useId hook. For example, some other dependency might use the one from reach-ui that this implementation is copied from.

Additionally, it makes the HTML in the DOM a bit easier to read, as react-day-picker-1 is easier to scan for and find.

Solution

Adding a prefix of react-day-picker- to the autogenerated ID-s will ensure the ID's generated from this hook are unique and will not conflict with other similar implementations.