chore(forms): forward component refs to DOM elements

[mhuggins]

NOTE: This PR is blocked until enzymejs/enzyme#1604 is fixed via enzymejs/enzyme#1592.

Description

This updates our form-based components to forward refs to the actual DOM element. This makes it so that the component does not need to expose functions specific to any element (e.g.: focus(), blur(), value).

Motivation and Context

Components should behave in an intuitive manner.

How Has This Been Tested?

Via the test suite and smoke testing.

Screenshots (if appropriate)

N/A

Types of changes

• Chore (tests, refactors, and fixes)
• New feature (adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• I have read the CONTRIBUTING guidelines and confirm that my code follows the code style of this project.
• Tests for the changes have been added (for bug fixes/features)

Documentation

• Docs need to be added/updated (for bug fixes/features)

Closing issues

N/A

[DalderupMaurice]

Should be unblocked now 😄

[mhuggins]

@DalderupMaurice They merged that PR, but they haven't published it in a release yet. I've been following closely. 😁

[codecov]

Codecov Report

Merging #412 into develop will decrease coverage by 1.23%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop     #412      +/-   ##
===========================================
- Coverage    54.06%   52.82%   -1.24%     
===========================================
  Files          156      154       -2     
  Lines         1230     1185      -45     
  Branches       156      150       -6     
===========================================
- Hits           665      626      -39     
+ Misses         477      471       -6     
  Partials        88       88

[mhuggins]

This is unblocked now. I've got some tests to fix up, and then this will be golden.

[mhuggins]

@DalderupMaurice This is ready for review now. 😃

[DalderupMaurice]

lgtm :P