[meta] Rename All The Fields!

Here are suggestions for renamings that I'd like to do before moving to SQL (to not make the SQL MR too big). Note that each renaming might imply other renamings, e.g. for functions touching these fields, in the client, etc.

Access

• Access.bank to Access.vendorId

Account

• Account.bank to Account.vendorId (or remove the field as suggested, since it's reachable from the access)
• Account.bankAccess to Account.accessId
• Account.accountNumber to Account.vendorAccountId (check if this behaves as an id for other models as commented?) (could even be vendorId if we removed the need for the current vendorId)
• Account.initialAmount to Account.initialBalance
• Account.lastChecked to Account.lastCheckDate
• Account.title to Account.label

Category

• Category.title to Category.label

Setting

• Setting.name to Setting.key
• rename all the keys to snake_case

Transaction

• Operation.title to Operation.label
• Operation.raw to Operation.rawLabel
• Operation.dateImport to Operation.importDate
• Operation to Transaction

It'd be nice if we could address each bullet point with a separate commit, maybe doing so in separate MRs even.

I wonder if we should rename booleans too with a systemic rule to prefix them by "is", to make it ultra obvious they're boolean values.

If you have better ideas for any of these names, or there's any other names that would need a renaming according to you, please add a comment so we can discuss it.