Add `--include-costs` option to `stellar network settings` to filter verbose cost params

[leighmcculloch]

What problem does your feature solve?

The stellar network settings command outputs the full network configuration including contract_cost_params_cpu_instructions and contract_cost_params_memory_bytes arrays. These cost params are extremely verbose (70 entries each) and make the output difficult to work with for most use cases.

This came up in stellar/stellar-rpc#563 where there was discussion about exposing network limits through RPC's getNetwork endpoint. The consensus was to not duplicate this functionality in RPC and instead point users to the CLI command, but the CLI output needs to be more usable by filtering out the verbose cost info by default.

See:

• Expand getNetwork endpoint response with core supported protocol version info (P25) stellar-rpc#563 (comment) (cc @Shaptic)
• Expand getNetwork endpoint response with core supported protocol version info (P25) stellar-rpc#563 (comment)

What would you like to see?

Add a new --include-costs flag:

• By default, exclude cost params from output
• With --include-costs, include the full cost params arrays

What alternatives are there?

Users can currently filter the output using jq:

stellar network settings --network testnet | jq 'del(.updated_entry[].contract_cost_params_cpu_instructions, .updated_entry[].contract_cost_params_memory_bytes)'

But this is cumbersome and requires knowing the field names to filter.