Allow better subclassing of MoneyField

[beerbohmdo]

Description

Move generation of NumberField from constructor to method to allow override in subclass.

Manual testing steps

Issues

• MoneyField: Move field generation from constructor to custom method #11153

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[GuySartorelli]

Seems sensible. Thanks for contributing!

Couple of small changes.
If there's an existing test for buildCurrencyField(), please add one for the new method as well.

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[beerbohmdo]

If there's an existing test for buildCurrencyField(), please add one for the new method as well.

There was no test for this method, I am not even sure what you wan't to test here. Nevertheless, I've added two test methods.

I will create a issue for this.

[GuySartorelli]

Thank you for the tests, that's fantastic! Exactly what I was after.

Just a couple of small things to tidy up, then I'll be happy to merge this.

[GuySartorelli]

Fantastic, thank you for implementing this and for your patience.