Indicated dirty/validity state for unit-based inputs

[justin-hackin]

Addresses:

• No visual indication of invalid unit-based number input after enter-submission
• Input does not re-insert unit on submission if erased (and the input label doesn't indicate unit)

The text input holds an intermediate value until the enter key is submitted. If the intermediate value matches the value in the property, it is valid. If the enter key was pressed but the input had invalid information, mark the field as errored. If the input text changes, mark as dirty.

State could be indicated with an icon inside input or with red/green background for field.