fix spelling of locale logged_in_successfully

[nspinazz89]

Description
Fix for #3345

Checklist:

• I have followed Pull Request guidelines
• I have added a detailed description into each commit message
• I have updated Guides and README accordingly to this change (if needed)
• I have added tests to cover this change (if needed)

[jacobherrington]

So this is a bit more complicated than I'd like it to be.

I think we are okay to merge this, but we will need to make a similar change in solidus_auth_devise.

It seems like this is something people have used for some time (based on a GitHub search). Hopefully the changelog will be enough to help people find this...

[jacobherrington]

Here are all of the places where we have used the misspelling: https://github.com/search?q=org%3Asolidusio+logged_in_succesfully&type=Code

[kennyadsl]

Here's another extension to be fixed: https://github.com/solidusio/solidus_i18n/search?q=logged_in_succesfully&unscoped_q=logged_in_succesfully

[kennyadsl]

Just commented on solidusio/solidus_auth_devise#173, and now I have other concerns (sorry): if a user updates solidus without updating solidus_auth_devise they'll end up having no translation for the old wrong string which is still used into solidus_auth_devise. The worst thing is that in this scenario the i18n fallback will auto-generate a wrong "Logged in succesfully"string.

That said, I'm tempted to ask you to leave both strings, but the solution proposed here won't have any effect at that point.

Maybe the safest thing for users is to keep both things (double keys here (and solidus_i18n) and the fallback default in solidusio/solidus_auth_devise#173). This way, users that update solidus will have an extra string in the i18n and in the future (maybe solidus 3.0), we will be able to safely remove the duplicated (wrong) string. What do you think?

[spaghetticode]

I agree with @kennyadsl, in order to play nice with every scenario we need to keep also the old key, and only later with a major release remove the misspelled one.

[kennyadsl]

@nspinazz89 can you please rebase this one?

[spaghetticode]

@nspinazz89 thank you 👍

[spaghetticode]

@nspinazz89 In order to improve git history readability, can you squash the commits into a single one? 🙏