wxGUI/g.gui.gcp: fix launch g.gui.gcp

[tmszi]

Move back wx.GridBagSizer sizer declaration into TitledPage base class, also required for wxGUI g.gui.gcp wizard pages.

To reproduce:

1. Launch g.gui.gcp

Error message:

Traceback (most recent call last):
  File "/usr/lib64/grass79/scripts/g.gui.gcp", line 71, in <module>
    main()
  File "/usr/lib64/grass79/scripts/g.gui.gcp", line 66, in main
    wizard = GCPWizard(parent=None, giface=StandaloneGrassInterface())
  File "/usr/lib64/grass79/gui/wxpython/gcp/manager.py", line 153, in __init__
    self.startpage = LocationPage(self.wizard, self)
  File "/usr/lib64/grass79/gui/wxpython/gcp/manager.py", line 370, in __init__
    self.sizer.Add(self.rb_maptype,
AttributeError: 'LocationPage' object has no attribute 'sizer'

This commit remove wx.GridBagSizer sizer declaration from base class TitledPage.

[petrasovaa]

I didn't realize the TitledPage was used elsewhere. The point of the change was to remove the GridBagSizer from the base class TitledPage because for some wizard pages different sizer is more advantageous, so I wanted to let them define the appropriate sizer.
Instead of putting the GridBagSizer back in there, I suggest creating a new class in location wizard, something like GridBagSizerTitledPage(TitledPage) that just adds the GridBagSizer there. Then change the classes for pages which still use that sizer. For the other GUI parts which use it, I would just change the import to from location_wizard.wizard import GridBagSizerTitledPage as TitledPage. This would apply to rlisetup, photo2image, image2target and gcp parts.

[tmszi]

I didn't realize the TitledPage was used elsewhere. The point of the change was to remove the GridBagSizer from the base class TitledPage because for some wizard pages different sizer is more advantageous, so I wanted to let them define the appropriate sizer.
Instead of putting the GridBagSizer back in there, I suggest creating a new class in location wizard, something like GridBagSizerTitledPage(TitledPage) that just adds the GridBagSizer there. Then change the classes for pages which still use that sizer. For the other GUI parts which use it, I would just change the import to from location_wizard.wizard import GridBagSizerTitledPage as TitledPage. This would apply to rlisetup, photo2image, image2target and gcp parts.

Thanks for the explanation, I thought similarly. I've already fixed it.

[petrasovaa]

Thanks!