add / update halls

[HeroPhil]

add / update halls functions

[HeroPhil]

no need for update function, functionality is not further pursued.

[christian-bettermann]

Function looks good so far, minor changes:

• add resolveRefs() on return statement so I see which rowtypes I added (right now I only handle with indexes for rowtypes but never see if it was the right one)
• name for hall should be required => default to undefined + error handle undefined hall name
• implement further error handling => was able to create a hall with rowtypes of "live/infastructure/rowtypes/undefined" while testing

[christian-bettermann]

• add documentation after revision

[HeroPhil]

disregard error handling