feat(sequencer): implement oracle module actions

[noot]

Summary

implement oracle module actions AddCurrencyPair and RemoveCurrencyPair

see https://github.com/skip-mev/connect/blob/main/proto/connect/oracle/v2/tx.proto and https://github.com/skip-mev/connect/blob/9ea31680774e2f71e683c0a4989df5bf2d5f2302/x/oracle/keeper/msg_server.go#L28 for relevant connect code

Background

these are required for the oracle authorities to be able to add/remove currency pairs from state; these are the pairs whose prices will be included in VEs.

Changes

• implement oracle module actions AddCurrencyPair and RemoveCurrencyPair
• make CurrencyPairState.QuotePrice optional, to reflect that this may not be set upon currency pair initialization (as no oracle price has been received for it)
• remove get/put_num_removed_currency_pairs from the oracle state_ext as it's not needed for our logic due to the fact that we execute txs in the proposal phase, so by the time vote extensions are issued for a block, the state has already been updated and currency pairs that are removed in that block have already been removed.

Testing

unit tests

Breaking Changelist

• adds new actions to the sequencer
• sequencer genesis is also updated (new fees)

Related Issues

part of # #1446