cannet v0.6.0

• attempts to reduce idle work, especially driven by plot
• mitigate long load times for plot signals when loading from cache/adding new plots/switching to previously unfocused plots
• overhaul settings system, improved settings UI
• add workspace concept per project. user can now create cannet project dir with .cannet_prj and .cannet dir. .cannet dir will hold data cache
• unity scaled CAN signals now rendered as hex
• units now in separate column from value in signals view
• plot scale changes
  • hidden enums no longer take up vertical space
  • hidden other signals no longer contribute to scale sizing
  • scale of constant-valued signals now contributes to the overall plot scaling; previously they'd sit smack in the middle of the plot area
• add ability to drag entire plot areas
• ensure scrolling shows up on project panel, trace (L/R), transmit, system messages
• ensure trace panel scroll bounds are updated when mesage signals are expanded
• allow editing selection filters in signal and plot panels
• attempt to mitigate unresponsiveness from adding many traces at once to an existing plot
• mouseover time in trace view now shows local time for the message timestamp
• free cursor in plot view now shows the time on the x axis
• rename python sidecar exe