Disable tools if active layer has no or unknown geometry
Create abstract classes for single and dual tools
[FEATURE] make multi to single tool dual mode
Include point in DualTool's default geometryType

exclude unknown geometry type
Harmonize function names of abstract tools
Add tooltip to dual tool
Make DtFlipLine a child of DtDualTool
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Create new abstract subclasses of DtDualTool

Make tools subclass of DtDualToolSelectFeature
Make DtFillRing a subclass of DtDualToolSelectVertex
Merge deleteRings into dtutils
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Make DtFillGap a subclass of DtDualToolSelectVertex
Renew tooltips
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Create two abstract classes for a single button/edit tool
Make DtProlongLine a subclass of DtSingleEditTool
Make DtCutWithPolygon a subclass of DtSingleButton
Add missing import