chore: libwaku - allow to properly set the log level in libwaku and unify a little (#2708)

* waku.nimble: set properly chronicles compilation flags for static libwaku
* adapt examples to new log setup

examples/rust/src/main.rs

@@ -63,7 +63,8 @@ fn main() {
         \"host\": \"127.0.0.1\",\
         \"port\": 60000, \
         \"key\": \"0d714a1fada214dead6dc9c7274581ec20ff292451866e7d6d677dc818e8ccd2\", \
-        \"relay\": true \
+        \"relay\": true ,\
+        \"logLevel\": \"DEBUG\"
     }";
 
     unsafe {