Turn restriction validator warning inconsistency

[Famlam]

Both TurnrestrictionTest.java and relation.mapcss throw a validation warning in the case of a turn restriction (relation with type=restriction) without a restriction=... key.
The mapcss one explicitly does not warn in case of restriction:mode=value (i.e. restriction:hgv=no_left_turn) instead of restriction=value. The java test however still gives an error in this case.

Basically there are two errors here:

1. A double warning is shown if no restriction key is present (the mapcss test seems superfluous)
2. The java test doesn't take into account transportation-mode-limited restrictions. According to the ​wiki, restriction:mode=* is also valid.

Expected: no warning if
restriction + type=restriction + restriction=no_left_turn
restriction + type=restriction + restriction:foot=no_left_turn

Expected: only 1 warning if
restriction + type=restriction

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-07-30 12:44:04 +0200 (Thu, 30 Jul 2020)
Build-Date:2020-07-31 01:30:49
Revision:16812
Relative:URL: ^/trunk

Identification: JOSM/1.5 (16812 nl) Windows 10 64-Bit
OS Build number: Windows 10 Home 2004 (19041)
Memory Usage: 817 MB / 1820 MB (142 MB allocated, but free)
Java version: 1.8.0_261-b12, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Look and Feel: com.sun.java.swing.plaf.windows.WindowsLookAndFeel
Screen: \Display0 1920x1080 (scaling 1.0x1.0)
Maximum Screen Size: 1920x1080
Best cursor sizes: 16x16 -> 32x32, 32x32 -> 32x32
Dataset consistency test: No problems found

Plugins:
+ OpeningHoursEditor (35414)
+ imagery_offset_db (35405)
+ pt_assistant (2.1.10-80-g7d9bba3)
+ tageditor (35258)
+ turnlanes-tagging (283)
+ undelete (35499)
+ utilsplugin2 (35487)

Map paint styles:
- https://josm.openstreetmap.de/josmfile?page=Styles/Lane_and_Road_Attributes&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/PublicTransport&zip=1

Validator rules:
+ %UserProfile%\Documents\tijdelijke bestanden\josm-eigen.validator.mapcss