Change the transaction pages to use <ion-datetime> element for date picker

[tloltman]

This should be done to the single-transaction in the Date input, and the recurring-transaction in the Start Date input, not the recurrence input yet.

For now we can just allow the date (month/day/year), we'll probably have to allow specific times eventually too. The element has attributes to determine what date values can be chosen and displayed. There will have to be a field on the class in the ts file for angular to store this value.

[tloltman]

Finished, merged to develop