Add information about the row indices that are outliers in OutliersDataCheck

[angela97lin]

Closes #2817

[codecov]

Codecov Report

Merging #2818 (be41d9e) into main (4d55cb1) will increase coverage by 0.1%.
The diff coverage is 100.0%.

@@           Coverage Diff           @@
##            main   #2818     +/-   ##
=======================================
+ Coverage   99.8%   99.8%   +0.1%     
=======================================
  Files        297     297             
  Lines      27755   27757      +2     
=======================================
+ Hits       27687   27689      +2     
  Misses        68      68             

Impacted Files	Coverage Δ
...ests/data_checks_tests/test_outliers_data_check.py	100.0% <ø> (ø)
evalml/data_checks/outliers_data_check.py	100.0% <100.0%> (ø)

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[freddyaboulton]

Looks good to me @angela97lin !