Add 'update' parameter in junos_config module (#19046)

* Add update parameter in junos_config module which supports
configuration action like merge, replace and overwrite.

* Add support for replace along with update
argument

lib/ansible/module_utils/junos.py

@@ -175,23 +175,12 @@ class Netconf(object):
             return ele
 
     def load_config(self, config, commit=False, replace=False, confirm=None,
-                    comment=None, config_format='text', overwrite=False):
-
-        if all([replace, overwrite]):
-            self.raise_exc('setting both replace and overwrite to True is invalid')
+                    comment=None, config_format='text', overwrite=False, merge=False):
+        if (overwrite or replace) and config_format == 'set':
+            self.raise_exc('replace/overwrite cannot be True when config_format is `set`')
 
         if replace:
             merge = False
-            overwrite = False
-        elif overwrite:
-            merge = False
-            overwrite = True
-        else:
-            merge = True
-            overwrite = False
-
-        if overwrite and config_format == 'set':
-            self.raise_exc('replace cannot be True when config_format is `set`')
 
         self.lock_config()