Modify J-Browse Wrapper to Accept Configurable Arranger Property

[b-f-chan]

Currently the J-Browse wrapper has a hardcoded model where it relies on a property from Arranger to explicitly be of value file.

We need to change the wrapper to instead accept a configurable property to meet the use case where people can use J-Browse in the Stage UI regardless of their own data models.

The proposal is to instead pass the value in as an environment variable, with default = file.

[b-f-chan]

@MitchellShiell will test this in playground

[b-f-chan]

@MitchellShiell we're moving this to low priority