Add and remove dynamic endpoints

[sevenhe1205]

Fix functions parametes

• Fix the value of the Name parameter passed to the subchannel in gproc_pool's disconnect_worker and remove_worker functions.

• grpcbox_subchannel contains three properties: Channel, endpoint, and Name. During initialization, grpcbox_subchannel calls the gproc_pool:connect_worker function with Channel and Name as parameters. When terminating, grpcbox_subchannel calls the gproc_pool:disconnect_worker and gproc_pool:remove_worker functions with incorrect parameters channel and endpoint. The correct parameters to use are channel and name.

Add and remove dynamic endpoints

• grpcbox_channel add add_endpoint and remove_endpoint functions

Add hash and direct pick strategies

• The grpcbox_client get_channel function adds support for hash and direct strategies
• gproc_pool:pick_worker uses the hash/direct policy. Options do not contain the Key parameter. gproc_pool:pick_worker uses the round_robin/random strategy

[tsloughter]

Thanks! Sorry I didn't get around to reviewing until now. Curious if you are using this add/remove endpoints feature in production?

[sevenhe1205]

yes, Service discovery requires grpcbox to have the ability to dynamic and drop endpoints, which we are ready to use in production

[tsloughter]

@sevenhe1205 can you rebase these changes?

I'm going to make a new grpcbox release but then would like to get your changes merged in and another release made.

[heshaoqiong1205]

@sevenhe1205 can you rebase these changes?

I'm going to make a new grpcbox release but then would like to get your changes merged in and another release made.

I lost my previous account, and this is a new one. I will rebase to the latest main branch. We discovered a new issue: when using the hash strategy, grpc_pool may cause the program to crash when adding and deleting workers. Therefore, we don't use the hash strategy in actual applications. Instead, we use the direct pick strategies.