Add deprecation warning for modifiedDates

[eileenmcnaughton]

Overview

Add deprecation warning for modifiedDates

This is only accessed from log_date

Before

Code appears to be inaccessible

After

Code appears to be inaccessible & is marked deprecated

Technical Details

Comments

[civibot]

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[demeritcowboy]

Looks like it was removed here: #15693 and here #15702

And I don't think force=1 works with advanced search so can't use it to do changelog searches that way.

[eileenmcnaughton]

@totten @seamuslee001 given we talked about this you might be interested to see our resident super sleuth tracked it down