[Patch] Test for proper "ele" values

[naoliv]

In ​https://wiki.openstreetmap.org/wiki/Key:ele we can see that ele is a numeric value that represents the elevation, in meters.

From ​#Local_Units we can assume that using units (even m for meter) is not needed (or is invalid).

If I am not lacking coffee, we have 8226 nodes, 3323 ways and 245 relations in OSM with an incorrect ele value ​http://overpass-turbo.eu/s/p0i

Is it useful to have this test in JOSM?

/* should be safe to just remove the meters unit from the value */
*[ele][ele =~ /^-?[0-9]+(\.[0-9]+)? ?m$/] {
        throwWarning: tr("{0} must be a numeric value, in meters and without units", "{0.key}");
        fixAdd: concat("ele=", trim(replace(tag("ele"), "m", "")));
        set .ele_is_fixed;
}

*[ele][ele !~ /^-?[0-9]+(\.[0-9]+)?$/]!.ele_is_fixed {
        throwWarning: tr("{0} must be a numeric value, in meters and without units", "{0.key}");
}

I am assuming that we can have negative values and that it's safe offer a fix to remove m from the value (for example, when ele=100m or ele=100 m)

Attached is also a small test case: nodes inside the green area should not receive any warning, nodes in orange should; nodes inside the yellow area are able to be automatically fixed.

[Klumbumbus]

In 12215/josm:

fix #14786 - Test for proper "ele" values (patch by naoliv)