[6.x] Improve the text fieldtype icon and the number icons

[JayGeorge]

Description of the Problem

• As per [6.x] Text field icon confusing #13696, the text fieldtype icon here looks like it's a required field because of asterisk

What this PR Does

• Closes [6.x] Text field icon confusing #13696 by removing the asterisk
• Rebalances the icon a little
• Tweaks the float and integer icons which were looking a bit weedy

How to Reproduce

1. Create a new field in the blueprint and check out the icon for the Text fieldtype, and also Float and Integer