GenesisValidator doesn't have `minimum_delegation_amount` and `maximum_delegation_amount`.

In tests we use `GenesisConfigBuilder` to setup validators. It should be possible to define `minimum_delegation_amount` and `maximum_delegation_amount`. Right now it forces us to use `add_bid`. It would be much easier if we don't have to build and execute `add_bid.wasm` for every validator on every test context setup.

Start by reading the GenesisConfigBuilder and GenesisValidator usage in the tests, then trace how add_bid.wasm currently supplies delegation limits during validator setup. Add support for defining minimum_delegation_amount and maximum_delegation_amount directly, and verify that test contexts can configure validators without building and executing add_bid.wasm for each validator.

Written by the indexing model from the issue text.