BF: allow getKeys() to return the same key pressed multiple times

[mh105]

(Replaces #6478 I accidentally messed up detached HEAD with psychopy/release using rebase in that PR. This one should be correct).

Fixes the bug of .getKeys() not returning the same key pressed multiple times using the change suggested by @TEParsons here.

This BF maintains the KeyPress() == KeyPress() comparison using only the name attribute.

[codecov]

Codecov Report

Attention: Patch coverage is 33.33333% with 2 lines in your changes are missing coverage. Please review.

Project coverage is 52.16%. Comparing base (5d1e515) to head (d5016a0).
Report is 50 commits behind head on release.

❗ Current head d5016a0 differs from pull request most recent head 846f671

Please upload reports for the commit 846f671 to get more accurate results.

Additional details and impacted files

@@             Coverage Diff              @@
##           release    #6479       +/-   ##
============================================
+ Coverage    41.63%   52.16%   +10.52%     
============================================
  Files          335      335               
  Lines        61863    61961       +98     
============================================
+ Hits         25757    32322     +6565     
+ Misses       36106    29639     -6467     

Components	Coverage Δ
app	∅ <ø> (∅)
boilerplate	∅ <ø> (∅)
library	∅ <ø> (∅)
vm-safe library	∅ <ø> (∅)

[TEParsons]

This looks good :) Just added a test so we don't backslide on this in future, once the test suite passes (it passed for me locally so I expect it to) I'm happy to pull in