sim_pin: support u32,s32,float pin,param types

Refactor to:
 Use tcl package (Hal) instead of halcmd
 Use popup to show errors
 Update displayed values by poll
   (makes visible changes by multiple sim_pin guis or other setters)
 Support signals if they have no writers
 Detect and report pins/params that are not writable, e.g.:
   pin    not IN nor I/O
   param  not RW
   pin    connected to signal
   signal connected to writer
 Support multiple columns of items