Add ability to set a non-zero commission schedule for a new validator/entity

[tjanez]

SUMMARY

Currently, when a new validator running with a new entity joins the network, it has no commission bounds defined, meaning, its commission rate is fixed at 0%.

To start earning commission, the validator/entity needs to amend its commission schedule and set the desired rates and rate bounds.

But it needs to set the commission rates and rate bounds for at least rate_bound_lead epochs in advance, which is currently set to 336 (approximately 14 days) on the Mainnet.

This lead period is meant to protect the delegators from validators changing (i.e. increasing) their commission rate unexpectedly.

However, when one is creating a new validator/entity, there are no delegators so the lead period doesn't make sense.

Hence, we should enable setting a non-zero commission schedule when creating a new validator/entity (similar to what can be done in the Genesis file).

ISSUE TYPE

• Feature Idea