Support generic adaptive issuance entrypoints

[Innkst]

1. Add support for the following Bakers related entry points to Taquito RPCClient:

• /context/adaptive_issuance_launch_cycle" - Returns the cycle at which the launch of the Adaptive Issuance feature is set to happen. A result of None means that the feature is not yet set to launch.
• /context/total_frozen_stake - Returns the total stake (in mutez) frozen on the chain
• /context/total_supply - Returns the total supply (in mutez) available on the chain

2. Make sure integration tests are created and passing