[Ecephys Support] Add SpikeGLXConverter support

[CodyCBakerPhD]

IDT @garrettmflynn was in this discussion from a while back, but the idea here is to add a radio switch to the data interface selector; the two states are 'simple' and 'advanced'

'simple' would replace the 'Spike GLX' title with the SpikeGLXConverter (a new addition to NeuroConv` under the hood. This is a format-specific subconverter (it can still be used in a session converter as if it were a data interface) that requires the SpikeGLX data to be stored in a specific way that is assumed to be the default storage during NeuroPixels acquisition. It's a more convenient class to use over the data interface because it only looks at the folder structure and instantiates across all available data streams from all probes and bands

'advanced' is still needed for fine-grain control over the data streams; it corresponds like it does now to a single SpikeGLXRecoridngInterface which applies to a single stream from a single probe and a single band. But that's why this would be an 'advanced' feature, it requires more tinkering than the 'simple' approach

'simple' would be the default state of the selector

A similar approach for other format-specific subconverters will be added over time, OpenEphys is currently the next planned one (ironically the current cases are likely SpikeGLX related) but Neuralynx would be a good candidate after that

[CodyCBakerPhD]

@garrettmflynn @rly Prioritizing this based on #356 but also because we're close to the point where we could use this now