Optimized email slicer

[franchsli]

Description

This Pull Request removes unnecesary looking operations in the EmailSlicer using Python unpacking feature and split() function
The Email Slicer uses index() twice which looks in the string twice

Fixes #

• Issue_no: ``````
• Not applicable

Type of change

Choosing one or more options from the following as per the nature of your Pull request.

• New project insert
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Documentation Update

Checklist:

Please tick all the boxes that are fulfilled by your Pull Request.

• I have named my files and folder, according to this project's guidelines.
• My code follows the style guidelines of this project.
• I have commented on my code, particularly in hard-to-understand areas.
• I have created a helpful and easy to understand README.md, according to the given README_TEMPLATE.
• My changes do not produce any warnings.