refactor(utils): Update gear-replay-cli tool

[ekovalev]

Aligns our custom gear-replay-cli tool with changes in underlying Substrate code. Also, following the original try-runtime-cli having been placed in the standalone repo under Parity Tech, synced our tool with its original predecessor.

More specifically,

• added support for state snapshots (which is useful for large states like our testnet, for instance, which is over 1.6GB at this point);
• fixed an error with forcing gear::run() extrinsic in a block: the filter based on comparing encoded extrinsics was unstable.

Note: the command format has naturally changed a bit - refer to the examples in README.md for the up to date syntax.