RedCraftChat 0.2.2-SNAPSHOT

Add a server selector, and a default server to land on

/servers opens a dialog of the backends, with a way straight back to the
one you came from at the top, and /servers <name> skips the dialog since
an argument means the player already knows where they are going. The
aliases follow: /hub and /s now run it rather than the proxy's /server.

Transfers go through createConnectionRequest rather than by running
/server for the player. That command lives on the proxy, this code is
already on the proxy, and going through it would mean handing the work
to a backend to hand straight back.

The setting underneath it answers a different question: where to put
someone at login. Three answers share one column, so "last server" is
stored as @last, spelled with a character a server id cannot contain,
because a network is free to register a backend called "last" and that
must not silently become a rule. With nothing set, the tick falls on
whatever the proxy's try list would have chosen, read from
getAttemptConnectionOrder rather than assumed to be the hub: it is the
hub today, but that is a fact about one config file, and a screen that
states it out loud should not be what goes stale when the file changes.

Two columns were added to rcc_player_preferences ahead of this, since
norm names every column in its SELECT and a missing one breaks reads for
every player rather than only writes.

The network is named from its own config key rather than borrowed from
the Discord activity string, so changing what Discord shows does not
reword an unrelated screen.