Canvas UI Component Update - Tabs

Fixes: CNVS-15537

Creates a new stylesheet in /components with our
updated tab styles from the brand styleguide.

Test plan:
- Open the /styleguide from the main Canvas URL.
- Click on Tab Navigation on the left menu
- Verify that both tab examples (default and minimal)
  are working
- I have found tabs being used in the following places
  in Canvas:
  - People
  - Calendar (click on a day to trigger the modal)
  - Settings (user, class, and site admin)
  - Site admin > Permissions
  - Site admin > Users > Groups
  - Quizzes (edit a quiz)

(Note for code review: jQueryUI inserts its own classes,
so consistent with Tabs, I did not create .ic- prefixed
classes.)

Change-Id: I2d346c2cd5d32483c8cf0d127e40b66c1397b820
Reviewed-on: https://gerrit.instructure.com/44583
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Colleen Palmer <colleen@instructure.com>
Product-Review: Colleen Palmer <colleen@instructure.com>
QA-Review: Nathan Rogowski <nathan@instructure.com>