Added improved StylableToast

[jaimehta19]

Fixes #102 🔐

Are you a part of GSSOC' 21 ❓

• Yes ✔️
• No ✖️

Describe the changes you've made 🏆

Added an attribute taken from the official repository of the StylableToast library to make it opaque which does not displays the underlying Texts or components which is overlapping

Type of change 🖇️

Please delete options that are not relevant.

• Bug fixing (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, local variables)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist: 📋

• My code follows the style guidelines of this project.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.
• Any dependent changes have been merged and published in downstream modules.

Screenshots (if required) 📷

Original	Updated