Refactor updated IEEG features (2/2)

[rcassani]

Refactor updated IEEG features (2/2)

This PR addresses pending issues (from PR #710) with the IEEG features.

Pending issues

• Display menu (for channel file with SEEG) does something different to the stated
  https://neuroimage.usc.edu/forums/t/46083
• Avoid closing all figures when starting a new implantation. If figures need to be closed, this must be selective:
  (Issue 1 in #701)
• Some Java exception issues
  https://neuroimage.usc.edu/forums/t/46585
  https://neuroimage.usc.edu/forums/t/46178
• Thresholding of isosurface without creating a new one
  Creating of a new file was supposed to be temporary (added in #689)
  Discussion: Do we need this file in the DB? It will used only on localizing contacts.
• Printing contact locations in GUI, better text alignment
  Discussion: Do we really need to print up to one-hundredth of millimeter?
• Display sensors in MRI 3D slices, add isosurface to figure (surface tab), add new SEEG electrode (in IEEG tab), enable Select tool (in EEG tab), click on isosurface. Result: MRI viewer opens (why?), all electrodes disappear of GUI and Electrode configuration is disabled. Electrodes are visible in 3D figure.
• Wrong CT volume can be selected thresholding CT with slider.
  See code: https://github.com/brainstorm-tools/brainstorm3/blob/master/toolbox/gui/panel_surface.m#L422-L426
• Slider in panel surface for thresholding CT is set only at panel creation (CreatePanel), thus it's hardcoded to 1 to 4500
  See code: https://github.com/brainstorm-tools/brainstorm3/blob/master/toolbox/gui/panel_surface.m#L113

Editing features for SEEG panel

• Move around and edit contacts in directly in 3D view (already directly possible in the MRI viewer)
• Shortcut to switch between center and non-center selection of 3D contacts
• Delete and add contacts while maintaining the ordering
• Regrouping contacts correctly for wrong grouping of contacts for a electrode
• Sanity check for auto-detected contacts with the electrode model

@tmedani, @chinmaychinara91