[form] Reduce and enforce DEFAULT_MIN_FILL_AMOUNT

[Atmosfearful]

Describe the bug
Change it from 1 to 0.001
Make sure ICR doesn't break (icr can't go below 1)
Make sure we are only using this value to set the min fill during listing creation, in other parts of the application we need to read the value provided for the actual listing (because old listings will still be 1, and future listings might someday be even more than that)
Use the minFillAmount value to validate the form here and prevent the user from trying to retire a value < the listing's min fill
https://www.carbonmark.com/projects/VCS-1764-2020/retire/0x734db5a54215c163b1372fb1cc860f40d6a90ccea89731433b9ca48cdc358039