"Copy" function for profile settings

[ofadam]

Feature description
When setting up small band segments in the web settings, it would be really great to be able to copy an existing profile setting when creating a new one. Then you wouldn't need to set things like gain, modulation, etc. from scratch.

Target audience
This would be of particular interest to those using Airspy devices, which have a smaller bandwidth.

[jketterl]

I would like to introduce something smarter, like e.g. profile ranges, but this will have to wait until this release is done and the migration is underway since i do not intend to make it downwards compatible with the manual configuration (config_webrx.py)