Added API getUserByName()

Tests and doc included

doc/api-user-procedures.markdown

@@ -113,6 +113,48 @@ Response example:
 }
 ```
 
+## getUserByName
+
+- Purpose: **Get user information**
+- Parameters:
+    - **username** (string, required)
+- Result on success: **user properties**
+- Result on failure: **null**
+
+Request example:
+
+```json
+{
+    "jsonrpc": "2.0",
+    "method": "getUserByName",
+    "id": 1769674782,
+    "params": {
+        "username": "biloute"
+    }
+}
+```
+
+Response example:
+
+```json
+{
+    "jsonrpc": "2.0",
+    "id": 1769674782,
+    "result": {
+        "id": "1",
+        "username": "biloute",
+        "password": "$2y$10$dRs6pPoBu935RpmsrhmbjevJH5MgZ7Kr9QrnVINwwyZ3.MOwqg.0m",
+        "role": "app-user",
+        "is_ldap_user": "0",
+        "name": "",
+        "email": "",
+        "google_id": null,
+        "github_id": null,
+        "notifications_enabled": "0"
+    }
+}
+```
+
 ## getAllUsers
 
 - Purpose: **Get all available users**