Extend Numbers field, various improvements

[timkelty]

Fixes #1, #3

Summary of changes:

• Field now directly extends craft\fields\Number, which removes a lot of duplicate code, allows defaultValue to be null, and gives us prefix/suffix.
• The matching field setting defaults now match Number:
  • defaultValue = null
  • size = null
  • decimals = 0
• Input Template
  • Field now in a flex wrapper (like Number field) to lay things out horizontally
  • unit is displayed using forms.textField's unit option

[khalwat]

So... do you need me to review this or... do you just wanna merge it yourself?

[nitech]

Heeey, any reason this is not merged?

[khalwat]

Waiting on @timkelty

[timkelty]

Same here.

[timkelty]

@nitech FWIW, I am using this on a production site…

I didn't have time to properly review it, which is why it remains unmerged.
On my list, though.

[nitech]

I understand. From what I see in the comments, @khalwat says he approves the code..?