set/2 : Pre parse/sort options to prevent wrong date creation

[Zarathustra2]

Steps to reproduce

iex(2)> date = ~D[2023-03-31]
~D[2023-03-31]
iex(3)> time =  ~N[2023-04-03 13:30:00]
~N[2023-04-03 13:30:00]
iex(4)> Timex.set(time, day: date.day, month: date.month, year: date.year)
~N[2023-03-30 13:30:00]
iex(5)> Timex.set(time, month: date.month, year: date.year, day: date.day)
~N[2023-03-31 13:30:00]
iex(10)> Timex.set(time, date: {date.year, date.month, date.day})
[date: {2023, 3, 31}]

Description of issue

• What are the expected results?
  The order of argument put into set/2 matters since Timex.set(time, day: date.day, month: date.month, year: date.year) will not always produce the same result as Timex.set(time, month: date.month, year: date.year, day: date.day)

Technically the user could/should have used the date option but this may not always be obvious.

I kinda propose to either pre parse the options to convert month, year & day options into a single date option or sort the options list by importance such that year is being set first, month second and day third (in our example).

What are you thinking?

Would happily work on this! :)

[Zarathustra2]

Oh there is a PR for this issue already: #671