Add finish button; goto specific step; various bug fixes

[Blackbaud-SteveBrush]

Issue(s):
https://github.com/blackbaud/skyux-progress-indicator/issues/20
https://github.com/blackbaud/skyux-progress-indicator/issues/16
https://github.com/blackbaud/skyux-progress-indicator/issues/15
https://github.com/blackbaud/skyux-progress-indicator/issues/14

Overview:

• Refactored imports, cleaned up unit and e2e tests.
• Ability to go to specific step via SkyProgressIndicatorMessage.
• Fix disabled state for buttons.
• Add finish button.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@20dcf36). Click here to learn what that means.
The diff coverage is 100%.

@@           Coverage Diff           @@
##             master    #17   +/-   ##
=======================================
  Coverage          ?   100%           
=======================================
  Files             ?     12           
  Lines             ?    394           
  Branches          ?     80           
=======================================
  Hits              ?    394           
  Misses            ?      0           
  Partials          ?      0

Impacted Files	Coverage Δ
...-indicator/types/progress-indicator-item-status.ts	100% <100%> (ø)
...utton/progress-indicator-reset-button.component.ts	100% <100%> (ø)
...es/progress-indicator/progress-indicator.module.ts	100% <100%> (ø)
...-button/progress-indicator-nav-button.component.ts	100% <100%> (ø)
...ndicator-item/progress-indicator-item.component.ts	100% <100%> (ø)
...rker/progress-indicator-status-marker.component.ts	100% <100%> (ø)
...progress-indicator/progress-indicator.component.ts	100% <100%> (ø)
...rogress-indicator/types/progress-indicator-mode.ts	100% <100%> (ø)
...indicator/types/progress-indicator-message-type.ts	100% <100%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 20dcf36...2eefdd3. Read the comment docs.

[Blackbaud-AlexKingman]

Great work on this. It's a huge improvement & nice style cleanup. See feedback below!

[Blackbaud-AlexKingman]

Lots of improvements in here. Great job 👍