Vueify Toast

[ElectronicBlueberry]

Adds a bootstrap vue based toast component, with a downwards compatible interface for existing uses of Toast.
Webhooks and toolshed still use Toastr.

A new success message.

How to test the changes?

(Select all options that apply)

• I've included appropriate automated tests.
• This is a refactoring of components with existing test coverage.
• Instructions for manual testing are as follows:
  1. [add testing steps and prerequisites here if you didn't write automated tests covering all your changes]

License

• I agree to license these and all my past contributions to the core galaxy codebase under the MIT license.