request help: share limit counter between routes

[spacewander]

Issue description

To do this, you need to specify the key of the route's corresponding limit-count in lrucache so that the same limit object is shared across multiple routes. lrucache keys (hereafter called groups to distinguish them from limit keys) are currently generated automatically, ensuring that each route's group is independent. For this change, we need to be able to specify the group in the limit-count.

"limit-count": {
            "group": "group_id_blah"
            "count": 2,
            "time_window": 60,
            "rejected_code": 503,
            "key": "remote_addr"
}

Note that the configuration of the same group needs to be the same, which currently needs to be guaranteed by the caller, otherwise the limit object obtained by the group will be different from the configuration.

Environment

• apisix version (cmd: apisix version): 2.10.1
• OS (cmd: uname -a):
• OpenResty / Nginx version (cmd: nginx -V or openresty -V):
• etcd version, if have (cmd: run curl http://127.0.0.1:9090/v1/server_info to get the info from server-info API):
• apisix-dashboard version, if have:
• the plugin runner version, if the issue is about a plugin runner (cmd: depended on the kind of runner):
• luarocks version, if the issue is about installation (cmd: luarocks --version):

[lanbiaowan]

i will take this