[brainstorm] policies for default `minrelaytxfee` as experiment for a release #25716

Is your feature request related to a problem? Please describe.

Some users have been curious about a lower minimum fee rate. A recent thread on mailing list:

https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2022-July/020784.html

Describe the solution you'd like

A new config option that changes the default minrelaytxfee to one of these for a minor release after v24.0:

1. Odd/Even: 0.001 sat/vB on odd dates and 1 sat/vB on even dates.
2. Market: 0.001 sat/vB during US market open hours else 1 sat/vB.
3. Interval: Starts with 0.001 sat/vB and keep changing after defined time interval

Describe alternatives you've considered

If enough users and miners agree to experiment this could be done without making changes in Bitcoin Core. Since most of the nodes use default it's difficult to experiment and know if one of these policies increase revenue for miners, provides better fee rates etc.

A related tweet thread: https://twitter.com/murchandamus/status/1480553169239355393

I think it should be tried by users without changing anything in code.