ENH: Adding X-Range Controls to Plot Settings

[zdomke]

Main Enhancement

Adding X-Axis controls to the PlotSettingsModal

• Mimics PR: ENH: Update X-Axis from QDateTimeEdits #17
• Added 2 new rows labeled "Start Time" and "End Time" each with a QDateTimeEdit to PlotSettingsModal
  • When a new date is set for either auto-scrolling will be turned off and the plot's x-axis will be changed
  • If the x-axis changes, the values in the QDateTimeEdits also change to reflect the updated x-axis range

Additional Fixes

Fix Auto-Scroll Interval

• TraceDisplay did not have a slot connected to the signal PlotSettingsModal.auto_scroll_interval_change
• Now it correctly adjusts the interval of the plot's auto scrolling feature by using the slot TraceDisplay.set_auto_scroll_interval

Constant for Disable Auto Scroll Button

• Set a constant value for the value of TraceDisplay.disable_auto_scroll_button
• Reasons for doing this:
  • It is set to a non-common value (-2) because -1 is a special value for QButtonGroups
  • The value is referenced in a couple places and the non-common value (-2) could cause confusion