[FEATURE REQUEST] Feature flag comparison

[sylvia-leaf]

*Is your feature request related to a problem? Please describe. If not, remove this field.
Now that the ISFe chunk is being parsed by the reference implementation, we need to implement logic for the feature flags system to allow the implementation to reject banks that use features that are not supported by the bank.

Is your feature related to the sound library or the app/website?
App/website

Describe the solution you'd like
Add a function that takes a list of supported features, compares this list with the feature flags read in the flag sub-chunk and ensures that all features are supported.

Describe alternatives you've considered
Just read the feature flags, but not enforce them. However, this means that the output is not always specified in the specification, meaning that the reference implementation would be unsuitable as a reference and thus not fit for purpose.

Additional context
SpessaSynth does not currently support all SF2.04 features (24-bit and NRPN are not supported). However, because the reference SFe bank does not use these flags, we would for now set these flags as unsupported.