[DISCUSS] PIP-364: Introduce a new load balance algorithm AvgShedder.

[thetumbled]

Hi, Pulsar Community.
    I open a new PIP to introduce a new load balance algorithm AvgShedder, 
which can fix some problems that current algo meet, such as load jitter, 
heterogeneous environment, slow load balancing, over placement problem, over 
unloading problem.
    I have done many tests to prove out my analysis and post them in the PR, 
hope them will be helpful to you!
    link: https://github.com/apache/pulsar/pull/22946

Thanks,
Wenzhi Feng(thetumbled)