Use tracing instead of log crate

Changed usubscription library to use generic tracing framework instead
of depending on env_logger crate. This allows users of the library
to choose their own logging backend.

Also updated up-subscription-cli to use tracing_subscriber as logging
backend and set up logging accordingly.

Removed obsolete None transport and related code and improved command
line argument handling for transport selection in up-subscription-cli.

Author: sophokles73

Cargo.lock

@@ -30,12 +30,11 @@ version = "0.4.0"
 
 [workspace.dependencies]
 async-trait = { version = "0.1" }
-env_logger = { version = "0.11" }
-log = { version = "0.4" }
 mockall = { version = "0.14" }
 protobuf = { version = "3.7.2" }
 test-case = { version = "3.3" }
 tokio = { version = "1", features = ["full"] }
+tracing = { version = "0.1", default-features = false, features = ["log", "std"] }
 up-rust = { version = "0.9.0", features = ["usubscription"] }
 up-subscription = { path = "./up-subscription" }
 

Cargo.toml

@@ -34,11 +34,20 @@ mqtt5 = ["dep:up-transport-mqtt5"]
 zenoh = ["dep:up-transport-zenoh", "dep:serde_json"]
 
 [dependencies]
-clap = { version = "4.5", features = ["derive", "env"] }
-clap-num = { version = "1.2" }
-log = { workspace = true }
+clap = { version = "4.5.53", default-features = false, features = [
+    "std",
+    "derive",
+    "env",
+    "color",
+    "help",
+    "usage",
+    "error-context",
+    "suggestions",
+] }
 serde_json = { version = "1.0", optional = true }
 tokio = { workspace = true }
+tracing = { workspace = true }
+tracing-subscriber = { version = "0.3", features = ["env-filter", "fmt"] }
 up-rust = { workspace = true }
 up-subscription = { workspace = true }
 up-transport-mqtt5 = { version = "0.4.0", optional = true }