Normalize slashes cross-platform

[dy]

We're doing npx ttag update ./i18n/en-CA.po ./src command.
In OSX that generates forward slashes:

#: src/constants.js:10

In windows that generates back slashes:

#: src\constants.js:10

That creates useless noise in git diff.
Can that be prob normalized?

[AlexMost]

Hi @dy!
Is it ok if we will leave only the first way of formatting?

[dy]

@AlexMost absolutely, I prefer / - that's the standard path style and windows understands that too.

[joaogardenberg]

Any hints on how to do that?
This still happens here.