Make the email checks case-insensitive

[ikusteu]

There was a problem where a customer signed up with CUSTOMER.NAME@gmail.com, the auth entry has been created and customer self registered. Afterwards, at some point, the customer tried logging in with customer.name@gmail.com. Since google auth is already case insensitive, the customer was able to authenticate, but since findCustomerByEmail looks for an exact match, the differently cased email didn't match and the customer was prompted to self register (rather than being redirected to their /customer_area page)

Tasks

• [ ] Fix the issue at hand (finding customer by email should be case insensitive)
• [ ] For all future registrations, I think it would be nice to have all emails lowercased (when signing up) and stored in the db lowercased (this is just a preference and, if the 1st task is taken care of, shouldn't have any notable effect)
• [ ] Check for other possible bugs stemming from this inconsistency and make the functionality tolerate mismatches in casing, where it makes sense

-note: it would probably be good to create a couple of string matching utils with different levels of strictness (in terms of whitespace, casing, etc...) and use those utils for string comparisons (in existing functionality and possible future one).

[silviot]

My proposal for a plan involves making sure that emails are always normalized when stored: lowercased and stripped of any whitespace possibly present.

• [x] Create a new function normalizeEmail that turns anExampleEmail@eXAMPLE.coM into anexampleemail@example.com.
• [x] change the code that stores emails into the db to normalize them before saving
• [x] write a migration script to normalize all existing emails
• [x] when searching for a matching email for user redirection, normalize it before querying firestore