[i18n] Use message ids for all translations to improve DX for CFAs

[jpzwarte]

Provide a general summary of the issue here

We should use https://lit.dev/docs/localization/overview/#message-ids for all the translations within our web components.

This will help CFAs in the following way:

1. Create a new web component with i18n: ${msg('Hello world')}
2. Run lit-localize extract
3. Edit <language>.xlf (for example nl.xlf) and add a translation "Hallo wereld"
4. Edit the web component and change the original text
5. After running step 2 again, our translation will be deleted

If in step 1 you instead write ${msg('Hello world', { id: 'welcome' })}, your translation will still be there in step 5.

This will make it a lot easier for CFAs to handle changes to the original text in the design system web components.

• document naming scheme

👤 Your name

Jeroen

🧢 Your Product/Team

SLDS