Unify rpc

[marioiordanov]

Usage related changes

Users can use http api endpoints via JSON-RPC api.

Development related changes

• Endpoints accessible via HTTP endpoints can be invoked via JSON-RPC
• StarknetRequest -> JsonRpcRequest
• StarknetResponse -> JsonRpcResponse (StarknetResponse, DevnetResponse, Empty)
• Most of the http api methods logic is extracted into <http api endpoint>_impl function which is called from JSON-RPC counterpart
• Updated docs

Checklist:

• [ ] Checked out the contribution guidelines
• [ ] Applied formatting - ./scripts/format.sh
• [ ] No linter errors - ./scripts/clippy_check.sh
• [ ] No unused dependencies - ./scripts/check_unused_deps.sh
• [ ] No spelling errors - ./scripts/check_spelling.sh
• [ ] Performed code self-review
• [ ] Rebased to the latest commit of the target branch (or merged it into my branch)
• [ ] Updated the docs if needed - ./website/README.md
• [ ] Linked the issues resolvable by this PR - linking info
• [ ] Updated the tests if needed; all passing - execution info

[marioiordanov]

For new JSON-RPC there is an issue created: https://github.com/0xSpaceShard/starknet-devnet-rs/issues/508