Fast Value/Type change of Voltage Source

[apantelopoulos]

Is your feature request related to a problem? Please describe.

The DC value of a voltage source cannot be changed from the Properties tab. If a different value is required, the Voltage Source has to be deleted and re-added.

Describe the solution you'd like
Voltage Sources should support instant value/type change from the Properties tab, as all other components do.

Describe alternatives you've considered
N/A

Additional context

Screenshot:

[tomcl]

The current properties page is implemented by two functions, one for V, one for RLCI. Probably there should be one function for VI and one for RLC since V& I should have similar functionality.