changing alert to toast message

[MaximilianoCabreraP]

I add toast.css file to style it.
I change all the alerts to the new "showToast" function that receives a message and a type (danger, warning and success)
At the bottom, I add the new features with manage the toasted message

Fixes #194

Fixing PR #195

Type of change
Please delete options that are not relevant.

[ x ] New feature (non-breaking change)

How Has This Been Tested?
Please describe the tests that you ran to verify your changes. Provide instructions so that they can be reproduced.

Test A
Test B
Checklist:
[ x ] My code follows the style guidelines of this project
[ x ] I have performed a self-review of my code
[ x ] I have commented my code, particularly in hard-to-understand areas
[ x ] I have made corresponding changes to the documentation
[ x ] My changes generate no new warnings
[ x ] Any dependent changes have been merged and published in downstream modules

[MaximilianoCabreraP]

Adding images to compare.
Preview:

Now: