Elements: Datatime - Rework the element

[walisc]

Currently we use the default datetime input, which has its fair share of problems . This ticket involves using an alternate library for the datetime component, and allowing it to be more configurable. This configurations change entail:-

1. Being able to change the display format
2. Being able to select between date time and date type
3. Allow nullable date

Accompanied to this should be selenium test to test the functionality