AoInput ui masking for date formatting

# Feature request summary

We would like to make date inputs easier and faster to use by implementing a ui mask, kind of like what is shown here: https://coreui.io/docs/components/masked-input/

AC
- When input is empty and not in focus, the placeholder expresses the date format. YYYY-MM-DD by default but users will be able to change this.
- When input is in focus, the placeholder remains
- As characters are typed, the placeholder values are replaced (this is how our client portal behaves for example)
- The dash (-) characters in the UI mask are part of the mask and not part of the palceholder. Ie. they are not typed over, they are just visual elements that break up the text

## Rationale

- Ensures numbers are input more consistently
- speeds up the process of typing numbers (no need to tab from year to month to day)
- communicates the date format to the user before and during input