Add 'only_randomx' and 'no_progpow' options to config

[who-biz]

• Removes need to specify these as arguments to server on initialization
• Both config options have no effect on mainnet (added is_test_network() boolean fn for checking)
• Above bulletpoint allows these flags to take effect only on AutomatedTesting, UserTesting, or Floonet ChainTypes

Tested and verified functional for cases:

1.) Floonet node where:

• a.) One or both config options are missing from config file
• b.) Both options set to true/false independently

2.) Mainnet node:

• Both options ignored if running server in mainnet mode