Prop 6: Tethys Upgrade (v1.5.1)

If it passes, this proposal will trigger Althea L1 to update to v1.5.1 and execute the Tethys upgrade.

The Tethys upgrade brings with it the following changes:
* Update Cosmos SDK to v0.46.16
* Update IBC to v6.3.1
* Update Ethermint to v0.22
* Add the Groups module, which enables easier collaboration for multisigs and therefore greater community proposal possibilities on Althea L1
* Add the FeeGrant module, which enables accounts to withdraw from another account's balances for fees
* Set the Distribution module's Base Proposer Reward parameter back to 0.5 (50%) and Bonus Proposer Reward back to 0.04 (4%)