feat: tolerate comma instead of dot typo in style value input

[kof]

Part of #3914

Description

Users often type comma instead of dot when entering css value numbers, we want to auto convert them to dot.

Steps for reproduction

1. type 1,2 in width input
2. hit enter, see it was converted to 1.2
3. type 1,2rem
4. hit enter, see it was converted to 1.2 and rem unit was applied

Code Review

• hi @kof, I need you to do
  • conceptual review (architecture, feature-correctness)
  • detailed review (read every line)
  • test it on preview

Before requesting a review

• made a self-review
• added inline comments where things may be not obvious (the "why", not "what")

Before merging

• tested locally and on preview environment (preview dev login: 5de6)
• updated test cases document
• added tests
• if any new env variables are added, added them to .env file