Implement editing functionality of all GeoLayers

[kb173]

We have these different GeoLayers which we want to edit:

• Vector
  • Points
  • Lines
  • Polygons
• Raster
  • RGB(A)
  • Float32
  • Byte

For Vector editing, we need to add points, move points, remove points, finish objects (e.g. stop the current line), and edit attributes.

For Raster editing, we want to change the value of pixels (to Color / number between 0 and 255 / any Float value). A color/value picker would also be useful. Different brushes would also be nice (size and fade-out).

[MathiasBaumgartinger]

Implementation of #254 before doing this would be advisable.

[MathiasBaumgartinger]

A current exemplary implementation works as follows:

f8d2160 implements a new - more generic - EditingAction and an ActionHandler. For each perspective an ActionHandler shall have three predifned actions: primary, secomdary, tertiary (mapping to e.g left, middle, right click). Each Perspective shall also have a duck typed equivalent of an AbstractCursor implementing certain functions. Furthermore EditingActions can be extended or used via special handle for additional cases.

36ab350 adds the input-map for 3D (primary -> left click, secondary -> right click, tertiary -> middle click)

278133f implements working functionality for GeoPoints. GeoPolygons and GeoLines seem to be currently limited by Geodot.

Working on RasterManagement next.

[MathiasBaumgartinger]

784e4a0 implements (very basic) functionality for raster editing.

Some functionality is currently limited by geodot specific problems:

• Newly created GeoLines do not seem to be returned geodot-plugin#76
• Implement functionality for GeoPolygon.set_outer_vertices(...) geodot-plugin#75
• Using GeoRasterLayer.smooth_add_value_at_position() requires to clean and rebuild overviews to show effect geodot-plugin#74

[kb173]

Raster editing is also related to boku-ilen/geodot-plugin#83