Client unsupported plugins check assumes map configuration contains at least one missing plugin

[sweco-semara]

Hajk client will currently always log the silent warning re. missing plugins in map config to the console, regardless if the config is clean/only contains active tools.

This bug is cosmetic only, mostly for developers or admins wanting to check that the Hajk config is correct. Current state is a bit confusing, but the map will still load without issues.

To Reproduce

1. Clean up a map configuration, make sure no inactive or invalid plugins are referenced
2. Open the browser console
3. (Re-)load the map
4. Check browser console

Expected behavior
Expect console to be quiet/empty if no errors.

Actual

The map configuration contains unavailable plugins: . Please check your map config and buildConfig.json.

Suggested fix
It seems there is a hard assumption in App.js that const unsupportedToolsFoundInMapConfig will always be set/contains at least one value. Suggested fix is to guard the join + console log operation on L397 in current master to not log if unsupportedToolsFoundInMapConfig is indeed empty.

[sweco-semara]

Will provide a patch against develop based on @jacobwod existing fixes on feature/1360-property-checker + hstd-main branches, see comment in 1391.