Validate prefix input in DA

[vburckhardt]

Consumer report:

For the prefix, I entered my prefix (with the capital letters) when providing DA parameters at the project level. There was no checking at that time and the failure occurred at one of the lower level DAs after 10 or so minutes.

[kierramarie]

@ocofaigh do we want to do prefix validation in this DA? In the PR there was discussion about this, saying that we don't need to because the account infrastructure base DA validates it however the core security stack does not call that DA.

[ocofaigh]

@kierramarie The new approach is that we will use a standard prefix validation for all DAs - please sync with @maheshwarishikha internally