[TextFields] Adds cursor color as parameter

[willlarche]

Found issue at stack overflow.

Closes #2296

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (develop@639941a). Click here to learn what that means.
The diff coverage is 88.57%.

@@            Coverage Diff             @@
##             develop    #2297   +/-   ##
==========================================
  Coverage           ?   45.95%           
==========================================
  Files              ?      231           
  Lines              ?    22597           
  Branches           ?     1924           
==========================================
  Hits               ?    10384           
  Misses             ?    12197           
  Partials           ?       16

Impacted Files	Coverage Δ
components/TextFields/src/MDCTextInput.h	92.85% <ø> (ø)
...xtFields/src/private/MDCTextInputCommonFundament.h	33.33% <ø> (ø)
components/TextFields/src/MDCMultilineTextField.m	79.47% <100%> (ø)
components/TextFields/src/MDCTextField.m	81.57% <100%> (ø)
...xtFields/src/private/MDCTextInputCommonFundament.m	90.6% <55.55%> (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 639941a...9b85d76. Read the comment docs.