[C++][Gandiva] Reduce dependency on vendored date.h library

### Describe the enhancement requested

Follow up on #48593 / #48601 - migrate remaining uses of `arrow_vendored::date` to ` arrow::internal::chrono`, using `std::chrono` where supported.

We now partially use `std::chrono`, but core parsing/formatting, Gandiva, and timezone configuration still
reference vendored code. The vendored timezone implementation is also compiled unconditionally.

We should retain vendored `date.h` for platforms where we cannot use `std::chrono`. We should preserve existing behavior and validate formatting edge cases, timezone transitions, etc.

This can be implemented incrementally, by adding required APIs to the existing `arrow::internal::chrono` shim with a conditional backend.

Related: #48743, #29371.

### Component(s)

C++, Gandiva