Added keyword to common.robot

- add new keyword to read files in common.robot
- fix one keyword in common.robot
- used new keyword in PRH suite
- use new keyword in dcaegen2 suite

Issue-ID: INT-661

Change-Id: I36cd2d5b82a20938a7b0775c9792dc2364a21922
Signed-off-by: Mariusz Wagner <mariusz.wagner@nokia.com>
diff --git a/test/csit/tests/common.robot b/test/csit/tests/common.robot
index 944be6b..8af66a5 100644
--- a/test/csit/tests/common.robot
+++ b/test/csit/tests/common.robot
@@ -1,22 +1,29 @@
 #Robot functions that will be shared also with other tests
+*** Settings ***
+Library     OperatingSystem
 
 *** Keywords ***
 json_from_file
 #Robot function to extract the json object from a file
     [Arguments]    ${file_path}
-    ${json_file}=    Get file    ${file_path}
+    ${json_file}=    Get File    ${file_path}
     ${json_object}=    Evaluate    json.loads('''${json_file}''')    json
-    [return]    ${json_object}
+    [Return]    ${json_object}
 
 string_from_json
 #Robot function to transform the json object to a string
     [Arguments]    ${json_value}
     ${json_string}=   Stringify Json     ${json_value}
-    [return]    ${json_string}
+    [Return]    ${json_string}
 
 random_ip
 #Robot function to generate a random IP
     [Arguments]
     ${numbers}=    Evaluate    random.sample([x for x in range(1, 256)], 4)    random
     ${generated_ip}=    Catenate    ${numbers[0]}.${numbers[1]}.${numbers[2]}.${numbers[3]}
-    [return]    ${generated_ip}
\ No newline at end of file
+    [Return]    ${generated_ip}
+
+Get Data From File
+    [Arguments]    ${file}
+    ${data}=    Get File    ${file}
+    [Return]    ${data}