query rpc tracker - sort servers by key name

[pfk-beta]

Hello,

I have created simple PR, currenly when I have multiple RPC server I can see then in random order, another issue is that ip address can have different length, e.g. 1.1.1.1 is 7, and 255.255.255.255 is 15, so the output may looks like:

Server List
----------------------------
server-address     key
----------------------------
172.31.8.8:5001 server:prague
172.31.8.3:5001 server:plex
172.31.8.12:5001        server:plex
172.31.8.4:5001 server:prague
172.31.8.13:5001        server:plex
172.31.8.5:5001 server:prague
172.31.8.13:5001        server:plex
----------------------------

after my changes:

Server List
------------------------------
server-address           key
------------------------------
     172.31.8.12:5001    server:plex
      172.31.8.3:5001    server:plex
     172.31.8.13:5001    server:plex
     172.31.8.13:5001    server:plex
      172.31.8.8:5001    server:prague
      172.31.8.4:5001    server:prague
      172.31.8.5:5001    server:prague
------------------------------

[pfk-beta]

another issue, when I review client code, is that total_ct can be converted to defaultdict(int), and computing max_key_len can be shortened to if-condition-assignment