[logger] use trace for low-level tracing info

[sebsto]

Is your feature request related to a problem? Please describe.
When using debug log level, there are really a lot of low level communication details that are generated by the library.

Describe the solution you'd like
Establish a clear framework to decide what information to log at debug level and trace level.
Key the low level byte receives / sent count at trace level for example.

Describe alternatives you've considered
Using a different logger for my app and for this library.

Additional context
Example of really verbose logs

2025-06-05T13:24:04+0200 debug bedrockcli : size=1469 [MCP] Message received
2025-06-05T13:24:04+0200 debug bedrockcli : id=1FCEA043-C2BB-4596-9E37-AAE4079D484B [MCP] Processing response
2025-06-05T13:24:04+0200 debug bedrockcli : size=7717 [MCP] Message received
2025-06-05T13:24:04+0200 debug bedrockcli : id=B90EFB53-A7D8-4467-AA6E-1D09D2C7FF7F [MCP] Processing response
2025-06-05T13:24:04+0200 debug bedrockcli : size=2399 [MCP] Message received
2025-06-05T13:24:04+0200 debug bedrockcli : id=D2864073-60D2-431B-865C-3E308EB3DBBF [MCP] Processing response
2025-06-05T13:24:04+0200 debug bedrockcli : size=297 [MCP] Message received
2025-06-05T13:24:04+0200 debug bedrockcli : id=C5C0F2D0-3837-44BD-AE76-CBF7DEBC7AB2 [MCP] Processing response

[mattt]

@sebsto I totally agree. Thanks for calling this out. I just opened up #130 to address this.

[sebsto]

Wow - that was fast :-) Thank you

[sebsto]

@mattt thank you for the quick response on this one.

I think we shoud also use debug for these info messages. wdyt ?

2025-06-07T23:28:49+0200 info bedrockcli : [MCP] Transport connected successfully
2025-06-07T23:28:49+0200 info bedrockcli : name=xxx version=1.0.0 [MCP] Client connected

2025-06-07T23:30:09+0200 info bedrockcli : [MCP] Initiating client disconnect...
2025-06-07T23:30:09+0200 info bedrockcli : [MCP] Transport disconnected

[sebsto]

@mattt The library is still very verbose, i.e. it issues many info-level message which is not a good thing to do for libraries.
Ideally, it should be silent at info level, and only use debug and trace

See https://www.swift.org/documentation/server/guides/libraries/log-levels.html

I can't reopen this issue, but I submitted a PR to remove the info - I let you decide if you want to delete the error and warning
#132