v0.2 editable coordinate workflow

[markseder]

Summary

Second development stage for OCR2Geometry for AutoCAD 2020.

Added

• editable X/Y coordinate DataGrid
• add row / delete selected rows
• Swap X/Y
• configurable start point number
• configurable label text height
• create DBPoint + DBText objects from the edited table
• CSV export (Point,X,Y)
• updated README and test instructions

Test in AutoCAD 2020

1. Build OCR2Geometry.sln.
2. NETLOAD the new DLL.
3. Run OCR2GEOMETRY.
4. Edit X/Y values, add/delete a row, test Swap X/Y.
5. Change start number and text height.
6. Click Create points and verify geometry/labels.
7. Click Export CSV and verify the saved file.

This PR should remain unmerged until the v0.2 build is validated locally in AutoCAD 2020.