Phase out opening_hours:covid19 field (#401)

…by making the field an optional field which is not displayed by default when selecting a preset. This approach allows mapeprs to easily see now potentially outdated pandemic opening hours and check/update/fix/convert them accordinly.

data/presets/highway/rest_area.json

@@ -3,13 +3,13 @@
     "fields": [
         "name",
         "operator",
-        "opening_hours",
-        "opening_hours/covid19"
+        "opening_hours"
     ],
     "moreFields": [
         "address",
         "email",
         "fax",
+        "opening_hours/covid19",
         "phone",
         "website",
         "wheelchair"

data/presets/highway/toll_gantry.json

@@ -11,10 +11,10 @@
         "access",
         "maxheight",
         "opening_hours",
-        "opening_hours/covid19",
         "payment_multi"
     ],
     "moreFields": [
+        "opening_hours/covid19",
         "website"
     ],
     "geometry": [