fix(button): Add mdc-typography-base to button

[lynnmercier]

Resolves #942

[codecov-io]

Codecov Report

Merging #949 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #949   +/-   ##
=======================================
  Coverage   99.93%   99.93%           
=======================================
  Files          68       68           
  Lines        3271     3271           
  Branches      403      403           
=======================================
  Hits         3269     3269           
  Misses          2        2

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