Preserve dtype on reset_index() in an empty DataFrame

[vaibhawc]

• closes reset_index() on MultiIndexed empty dataframe does not preserve dtypes  #19602

[pep8speaks]

Hello @vaibhawc! Thanks for submitting the PR.

• There are no PEP8 issues in the file pandas/core/frame.py !

[codecov]

Codecov Report

Merging #23856 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master   #23856   +/-   ##
=======================================
  Coverage   92.28%   92.28%           
=======================================
  Files         161      161           
  Lines       51500    51500           
=======================================
  Hits        47528    47528           
  Misses       3972     3972

Flag	Coverage Δ
#multiple	90.68% <100%> (ø)	⬆️
#single	42.31% <0%> (ø)	⬆️

Impacted Files	Coverage Δ
pandas/core/frame.py	97.02% <100%> (ø)	⬆️

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[datapythonista]

Thanks for the contribution @vaibhawc can you add unit tests and a whatsnew note on what is being fixed?

[jreback]

needs tests

[datapythonista]

Closing as stale, @vaibhawc if you want to continue working on it, please address comments and reopen the PR.