Accompany quantities with their respective UoMs

[bosue]

In the editable grid, item quantity unfortunately isn‘t presented with its accompanying UoM.

From this perspective, it‘s impossible to see whether these are 2.5 meters, 2.5 feet or 2.5 kilogram of cotton fabric, as it‘s impossible to see whether the 5 units of bleach come per liter or per liquid gallon.

Solving this would require two things:

• [ ] Support for non-editable pre- and suffices, see frappe/frappe#22403
• [x] UoM abbreviations, as we certainly want the suffix to be a simple “m” rather than “Meters”, “kg” rather than “Kilograms” and “gal” rather than “Gallons, U.S. liquid”

[barredterra]

https://github.com/frappe/erpnext/pull/40593 added an abbreviation ("Symbol") to the UOM doctype