Add a start location picker

[Terreii]

Is your feature request related to a problem? Please describe.
At the moment, Andromeda only allows to login to the last location. But all other viewers allow to login to other locations.

Describe the solution you'd like
Add a selection to the login components. It should have following options:

• Last location
• Home
• And, optionally, an input here the user can enter a SLURL for their start location.

Describe alternatives you've considered
Add an info text the the last location will be the start location.

Additional context
Radegasts implementation can be used for the reference for parsing the SLURL. Or from the Linden Viewer.
There is also a knowledgebase article about SLURLs.