dynamic category placeholder

[KRChapman]

@AndyatFocallocal If the btm map is using fl-sleeper this will fix the 'Event Category' to 'Resource Category'

[AndyatFocallocal]

@KRChapman it shouldn't be using sleeper so i'll leave this for until checking to see if your previous PR fixes it on the live map. I suspect that the live map is still loading the sleeper branch, if so we need to work out why it is.

both sites should now be loading master_withoutDCS branch, and using i18n to define any differences we need