Feature: Master password to startup application

[JBtje]

I do not know how the passwords are stored, though I would imagine they can easily be restored/made readable (e.g. the passwords stored by MySQL Workbench can be obtained using 5 lines of Python).

So, the workflow I would like to request:

• Start TablePlus
• Prompt for a master password (to unlock encrypted configuration)
• if no password is provided, show the connections that are not encrypted
• if password is provided, show all connections