Add an HTTP API endpoint + UI widgets to stream logs (#49)

* Added JSON logs to Desktop

* Move logging config into librqbit for reuse

* Log printer now available in both Desktop and Web UI

* Fix JS type error

Cargo.lock

@@ -2667,6 +2667,16 @@ dependencies = [
  "tracing-core",
 ]
 
+[[package]]
+name = "tracing-serde"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bc6b213177105856957181934e4920de57730fc69bf42c37ee5bb664d406d9e1"
+dependencies = [
+ "serde",
+ "tracing-core",
+]
+
 [[package]]
 name = "tracing-subscriber"
 version = "0.3.18"
@@ -2677,12 +2687,15 @@ dependencies = [
  "nu-ansi-term",
  "once_cell",
  "regex",
+ "serde",
+ "serde_json",
  "sharded-slab",
  "smallvec",
  "thread_local",
  "tracing",
  "tracing-core",
  "tracing-log",
+ "tracing-serde",
 ]
 
 [[package]]