Add default FacetGrid titles on initialization instead of after plotting

[Denbergvanthijs]

Lets see if any tests will fail. It passed thru tests and linting on my own machine.

Fixes #2702

[codecov]

Codecov Report

Merging #2705 (8f9d2fb) into master (d4aa367) will not change coverage.
The diff coverage is 100.00%.

❗ Current head 8f9d2fb differs from pull request most recent head bfcf8c9. Consider uploading reports for the commit bfcf8c9 to get more accurate results

@@           Coverage Diff           @@
##           master    #2705   +/-   ##
=======================================
  Coverage   97.53%   97.53%           
=======================================
  Files          17       17           
  Lines        6439     6439           
=======================================
  Hits         6280     6280           
  Misses        159      159           

Impacted Files	Coverage Δ
seaborn/axisgrid.py	96.07% <100.00%> (ø)

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[mwaskom]

This looks good. Can you add an entry in the release notes?

[Denbergvanthijs]

Added! Feel free to change the text, English is not my native language. Thank you very much for the fast responses!

[mwaskom]

Perfect. Thanks!