Tokens available to use in email subject and body fields not reflecting

FIxed the issue.
Please Review the MR.

Tested on local.
The changes look good.

Just left 2 minor comments in the MR regarding the code comments.

Rest is good to merge.

Thank you Vivek Panicker for the suggestion. Updated the MR accordingly.

Works great. Can't believe this has not been addressed after half a year as tokens worked until version 2.6. and this basically makes the module unusable.
RTBC