Merge bitcoin/bitcoin#22530: log: sort logging categories alphabetically

d596dba987 test: assert logging categories are sorted in rpc and help (Jon Atack)
17bbff3b88 log, refactor: use guard clause in LogCategoriesList() (Jon Atack)
7c57297319 log: sort LogCategoriesList and LogCategoriesString alphabetically (Jon Atack)
f720cfa824 test: verify number of categories returned by logging RPC (Jon Atack)

Pull request description:

  Sorting the logging categories seems more user-friendly with the number of categories we now have, allowing CLI users to more quickly find a particular category.

  before
  ```
  $ bitcoin-cli help logging
  ...
  The valid logging categories are: net, tor, mempool, http, bench, zmq, walletdb, rpc, estimatefee, addrman, selectcoins, reindex, cmpctblock, rand, prune, proxy, mempoolrej, libevent, coindb, qt, leveldb, validation, i2p, ipc

  $ bitcoind -h | grep -A8 "debug=<category>"
    -debug=<category>
         ...
         output all debugging information. <category> can be: net, tor,
         mempool, http, bench, zmq, walletdb, rpc, estimatefee, addrman,
         selectcoins, reindex, cmpctblock, rand, prune, proxy, mempoolrej,
         libevent, coindb, qt, leveldb, validation, i2p, ipc.

  $ bitcoin-cli logging [] '["addrman"]'
  {
    "net": false,
    "tor": true,
    "mempool": false,
    "http": false,
    "bench": false,
    "zmq": false,
    "walletdb": false,
    "rpc": false,
    "estimatefee": false,
    "addrman": false,
    "selectcoins": false,
    "reindex": false,
    "cmpctblock": false,
    "rand": false,
    "prune": false,
    "proxy": true,
    "mempoolrej": false,
    "libevent": false,
    "coindb": false,
    "qt": false,
    "leveldb": false,
    "validation": false,
    "i2p": true,
    "ipc": false
  }
  ```

  after

  ```
  $ bitcoin-cli help logging
  ...
  The valid logging categories are: addrman, bench, cmpctblock, coindb, estimatefee, http, i2p, ipc, leveldb, libevent, mempool, mempoolrej, net, proxy, prune, qt, rand, reindex, rpc, selectcoins, tor, validation, walletdb, zmq

  $ bitcoind -h | grep -A8 "debug=<category>"
    -debug=<category>
         ...
         output all debugging information. <category> can be: addrman,
         bench, cmpctblock, coindb, estimatefee, http, i2p, ipc, leveldb,
         libevent, mempool, mempoolrej, net, proxy, prune, qt, rand,
         reindex, rpc, selectcoins, tor, validation, walletdb, zmq.

  $ bitcoin-cli logging [] '["addrman"]'
  {
    "addrman": false,
    "bench": false,
    "cmpctblock": false,
    "coindb": false,
    "estimatefee": false,
    "http": false,
    "i2p": false,
    "ipc": false,
    "leveldb": false,
    "libevent": false,
    "mempool": false,
    "mempoolrej": false,
    "net": false,
    "proxy": false,
    "prune": false,
    "qt": false,
    "rand": false,
    "reindex": false,
    "rpc": false,
    "selectcoins": false,
    "tor": false,
    "validation": false,
    "walletdb": false,
    "zmq": false
  }
  ```

ACKs for top commit:
  theStack:
    re-ACK d596dba987

Tree-SHA512: d546257f562b0a288d1b19a028f1a510aaf21bd21da058e7c84653d305ea8662ecb4647ebefd2b97411f845fe5b0b841d40d3fe6814eefcb8ce82df341dfce22

test/functional/rpc_misc.py

@@ -54,13 +54,27 @@ class RpcMiscTest(BitcoinTestFramework):
 
         assert_raises_rpc_error(-8, "unknown mode foobar", node.getmemoryinfo, mode="foobar")
 
-        self.log.info("test logging")
+        self.log.info("test logging rpc and help")
+
+        # Test logging RPC returns the expected number of logging categories.
+        assert_equal(len(node.logging()), 24)
+
+        # Test toggling a logging category on/off/on with the logging RPC.
         assert_equal(node.logging()['qt'], True)
         node.logging(exclude=['qt'])
         assert_equal(node.logging()['qt'], False)
         node.logging(include=['qt'])
         assert_equal(node.logging()['qt'], True)
 
+        # Test logging RPC returns the logging categories in alphabetical order.
+        sorted_logging_categories = sorted(node.logging())
+        assert_equal(list(node.logging()), sorted_logging_categories)
+
+        # Test logging help returns the logging categories string in alphabetical order.
+        categories = ', '.join(sorted_logging_categories)
+        logging_help = self.nodes[0].help('logging')
+        assert f"valid logging categories are: {categories}" in logging_help
+
         self.log.info("test echoipc (testing spawned process in multiprocess build)")
         assert_equal(node.echoipc("hello"), "hello")