Added vehicles to database and supporting methods

[castaway]

Optional vehicle number plate storage for members, to assist us passing this to BSS house for ANPR system:

• Persons (members) can have 0-many vehicles, identified by a number plate string, and a date added
• Register person form includes an (optional) field to add an initial vehicle
• Telegram bot allows members (must be identified) to add vehicles
• Vehicle plates can be max 7-chars long, any spaces and non-letter/digit characters will be removed
• Profile view lists existing vehicles
• List-all-vehicles (plates) list outputs plates of all current members