Add netty logging handler to log HTTP requests/responses

[veebs]

Add pipeline.addLast("log", new LoggingHandler())

into PipelineFactory class if WebServerConfig field logNetworkActivity flag is set to true.

This will output the HTTP requests and responses to the log when the log level is set to DEBUG.

15:42:47.773 [DEBUG] [nioEventLoopGroup-3-1] [] [i.n.handler.logging.LoggingHandler] [] - [id: 0x67a307ff, /127.0.0.1:47756 => /127.0.0.1:9002] RECEIVED(255B)
         +-------------------------------------------------+
         |  0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f |
+--------+-------------------------------------------------+----------------+
|00000000| 47 45 54 20 2f 77 65 62 73 6f 63 6b 65 74 2f 73 |GET /websocket/s|
|00000010| 75 62 70 72 6f 74 6f 63 6f 6c 73 2f 20 48 54 54 |ubprotocols/ HTT|
|00000020| 50 2f 31 2e 31 0d 0a 55 70 67 72 61 64 65 3a 20 |P/1.1..Upgrade: |
|00000030| 77 65 62 73 6f 63 6b 65 74 0d 0a 43 6f 6e 6e 65 |websocket..Conne|
|00000040| 63 74 69 6f 6e 3a 20 55 70 67 72 61 64 65 0d 0a |ction: Upgrade..|
|00000050| 53 65 63 2d 57 65 62 53 6f 63 6b 65 74 2d 4b 65 |Sec-WebSocket-Ke|
|00000060| 79 3a 20 4a 36 38 5a 51 63 67 36 4c 42 43 59 70 |y: J68ZQcg6LBCYp|
|00000070| 6e 52 54 45 30 6f 38 64 77 3d 3d 0d 0a 48 6f 73 |nRTE0o8dw==..Hos|
|00000080| 74 3a 20 6c 6f 63 61 6c 68 6f 73 74 3a 39 30 30 |t: localhost:900|
|00000090| 32 0d 0a 53 65 63 2d 57 65 62 53 6f 63 6b 65 74 |2..Sec-WebSocket|
|000000a0| 2d 4f 72 69 67 69 6e 3a 20 68 74 74 70 3a 2f 2f |-Origin: http://|
|000000b0| 6c 6f 63 61 6c 68 6f 73 74 3a 39 30 30 32 0d 0a |localhost:9002..|
|000000c0| 53 65 63 2d 57 65 62 53 6f 63 6b 65 74 2d 50 72 |Sec-WebSocket-Pr|
|000000d0| 6f 74 6f 63 6f 6c 3a 20 64 6f 6e 74 6b 6e 6f 77 |otocol: dontknow|
|000000e0| 0d 0a 53 65 63 2d 57 65 62 53 6f 63 6b 65 74 2d |..Sec-WebSocket-|
|000000f0| 56 65 72 73 69 6f 6e 3a 20 31 33 0d 0a 0d 0a    |Version: 13.... |
+--------+-------------------------------------------------+----------------+