Normalize decimal separators in perps trigger order input formatting

[davidullo]

Fixes APP-####

What changed (plus any additional context for devs)

As shown in the screen recording, when entering a stop loss or take profit price with a keyboard that uses commas as decimal separators, the formatter strips commas and only allows dots, blocking valid decimal input unless the keyboard provides a dot

Screen recordings / screenshots

https://github.com/user-attachments/assets/91d34bdb-c0f8-4d9c-ae22-6abf9e192562

What to test