Add ability to override wrapper styles on resize-sensor

[KealJones]

Ultimate problem:

ResizeSensor wrapper forces certain inline styles

How it was fixed:

Added mergedStyles to apply to wrapper styles so that users can override the inline styles.

Testing suggestions:

1. pull branch
2. run ddev test test/over_react_component_test.dart

Potential areas of regression:

This could cause issues issue to how the resizesensor functions if used incorrectly but allows more consumer control.

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FYA: @greglittlefield-wf @aaronlademann-wf @evanweible-wf @maxwellpeterson-wf

[aviary-wf]

Security Insights

No security relevant content was detected by automated scans.

Action Items

• Review PR for security impact; comment "security review required" if needed or unsure
• Verify aviary.yaml coverage of security relevant code

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[codecov-io]

Codecov Report

Merging #190 into master will increase coverage by 0.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #190      +/-   ##
==========================================
+ Coverage   94.48%   94.49%   +0.01%     
==========================================
  Files          34       34              
  Lines        1630     1632       +2     
==========================================
+ Hits         1540     1542       +2     
  Misses         90       90

[greglittlefield-wf]

LGTM, but I think we should do an audit to ensure no one's depending on this behavior (i.e., they're passing in styles that collide with those added by ResizeSensor, and would break once they're no longer overridden).

[kealjones-wk]

I took a quick look around github...
https://github.com/search?p=1&q=ResizeSensor+org%3AWorkiva+style&type=Code

I can't seem to find anyone that is using the style attribute on a ResizeSensor.