change account prefixes for testing

[goastler]

[goastler]

[0x0; 32] and [0x1; 32] are used by default in the testing environment, which can leads to issues by duplication of accounts or calling from the default [0x1; 32] when that accounts has been used as a role, e.g. provider, leading to pass or fail of tests when they shouldn't.

We either need to add a constant at the end of our test accounts or change the prefixes. I think the former would be better, otherwise we're always open to a clash in the future if someone forgets about this issue