Refactor components dealing with Date and Time

[davezuch]

What does this pull request do?

Continuing on the work started in #156 and #166, we move DateTimePicker, DatePicker, and TimePicker to the top-level.

Where should the reviewer start?

Commit-by-commit.

Other Notes:

The changes here constitute a breaking change. If you want to validate these changes in Wildcat or OMS, you can:

1. In the project's packages.dhall, change the Ocelot version to:

   - , version = "v0.27.0"
   + , version = "origin/davezuch/datetime-components"

2. In Wildcat, run these sed commands to change the relevant module names:

   find web/purs/src -type f -name '*.purs' | xargs sed -i 's/Ocelot.Components.DateTimePicker.Component/Ocelot.DateTimePicker/g'
   find web/purs/src -type f -name '*.purs' | xargs sed -i 's/Ocelot.Components.DatePicker.Component/Ocelot.DatePicker/g'
   find web/purs/src -type f -name '*.purs' | xargs sed -i 's/Ocelot.Components.TimePicker.Component/Ocelot.TimePicker/g'

   In OMS, we only use the DateTime picker, so the sed commands should just be:

   find infrastructure/src -type f -name '*.purs' | xargs sed -i 's/Ocelot.Components.DateTimePicker.Component/Ocelot.DateTimePicker/g'

After the above steps, the project should build successfully.

[davezuch]

Thanks for the review!