Speed up Amendment activation

In the XRPL protocol, absent any exceptional measures, the fastest a given Amendment can activate is two weeks. This is due to the two-week delay between an Amendment reaching Majority and when it is Activated.

For testing purposes, it is necessary to accelerate Amendment activation on a private or parallel network. For example, you may want an Amendment to activate in 1 hour.

The parameter is set here: https://github.com/XRPLF/rippled/blob/develop/src/ripple/protocol/SystemParameters.h#L83-L84

This can be set in the rippled.cfg config file with [amendment_majority_time].

The format must be: [0-9]+ [minutes|hours|days|weeks]

Due to the interval of flag ledgers, amendment_majority_time should be set to 15 minutes or longer. Common values used on past test networks include 30 minutes and 48 hours. As mentioned above, the default is 2 weeks, ensuring node/validator operators typically have at least 2 weeks to avoid being amendment blocked.

Use rippled feature [feature name] accept to enable. Use rippled feature to check when it is enabled.

Parallel (including test) networks should use a random, unused network_id > 1024. Transactions for that network must include the matching NetworkID.