Use code in MultipolygonTest to improve CreateMultipolygonAction

[GerdP]

A few things which are not good:

• Performance is poor when you update a complex multipolygon (MP) since MultipolygonBuilder uses complex area intersections
• In special cases a created or updated MP might be flagged as incorrect by validator (MultipolygonTest)

My idea: The calculations in MultipolygonTest are using a faster implementaion to detect the inner and outer ways (as well as geometry errors), it only requires a few lines of code to implement a method makeFromWays(Collection<Way> ways) similar to that in MultipolygonBuilder and all the validation result (list of TestErrors) comes for free.
In a further step I plan to use this to improve Selector.CrossingFinder.

[GerdP]

Proof of concept, I am not yet 100% sure how to handle update of an invalid MP (e.g. node as member)

[GerdP]

In 15141/josm:

see #17767 and #17768: add non regression unit tests
Test testTicket17768() fails with current code and is ignored for now.

[GerdP]

I am stepping through the unit test samples in data_nodist\multipolygon.osm
I think the "Update multipolygon" action should also fix some erros, esp.

• all member roles should be set correctly (okay)
• area style tags on outer ways should be moved to the mp relation (if correct old style mp) (okay)
• duplicate members should be removed (not done without the patch)
• non-Way members should be removed, although they are allowed in type=boundary relations (not done without the patch)
• invalid geometries should produce a message (okay)
• relation "06/04 - Mismatching way styles" should produce a warning (not done, also not with the patch)

[GerdP]

improved version

[GerdP]

In 15160/josm:

fix #17768: Use code in MultipolygonTest to improve CreateMultipolygonAction

• implement new method makeFromWays() in MultipolygonTest
• let MultipolygonBuilder.makeFromWays() use the new method, it is much faster and detects more cases where the geometry is invalid.
• remove now obsolete code in MultipolygonBuilder, add javadoc for some public fields
• let CreateMultipolygonAction use the new method and add some code to improve user feedback when update removes members or when nothing was changed but the relation is still not a valid multipolygon.
• let Geometry use final field JoinedPolygon.nodes instead of method JoinedPolygon.getNodes() as this is not a getter but a calculation routine which should be changed later.

[GerdP]

In 15162/josm:

see #17768: activate unit test

[GerdP]

Create / update multipolygon no longer works when inner rings share segments.

[GerdP]

In 15183/josm:

fix #17768: Create / Update multipolygon did not work wich touching inner rings