Restructure action_plugins implementation to fix issue in ansible==2.9

[rsmekala]

Fixes issue #465.

Changes

• Move ActionModule implemetaion from module_utils/juniper_junos_common.py to action_plugins/juniper_junos_common_action.py
• Dropped support for Juniper.junos==1.4.3 module naming e.g junos_get_facts, junos_get_config.
• Replaced convert_to_bool_func with Ansible's implemetaion of boolean.

[rsmekala]

@vnitinv Updated the code as discussed offline.

[vnitinv]

looks good.

[vnitinv]

@rsmekala Can you add UT result here?

[rsmekala]

ok to test

[rsmekala]

retest this please

[rsmekala]

retest this please

[rsmekala]

@vnitinv UT is passing. Please merge the PR.

[vnitinv]

Looks good

[paleblued0t]

I believe we may want to add this to handle the TypeError exception that boolean throws when the value cannot be converted.

                if allow_bool_values is True:
                    # Try to convert it to a boolean value. Will be None if it
                    # can't be converted.
                    try:
                        bool_val = boolean(v)
                    except:
                        bool_val = None