dev/report#5 - Fix mailing report unique count issue

[monishdeb]

Overview

Steps to replicate:

1. Go to Mailing >> Scheduled and Sent Mailings >> Report
2. Unique Opens -> (click) Report
3. Total Opens -> (click) Report

Both Report show same count.

Before

Both Report showing same count (Unique report is in-correct)

After

Unique Opens Report has less value as compared to Total Opens

[civibot]

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[monishdeb]

@sunilpawar I have cherry-picked your commit and on top of the patch I made the following changes:

1. Modified UT to work with test data
2. Minor optimization in code
3. Removed the FGB handling in the groupBy() as it is no longer required ($this->optimisedForOnlyFullGroupBy = FALSE is declared in report)

and this is the last commit

I realized later why you have to bring a separate parameter 'distinct' instead of using the unique_opens_value=Yes/Any, as not to change the core behavior of MailingOpened Report.

@eileenmcnaughton @sunilpawar do you agree with the final patch?

[sunilpawar]

@monishdeb i am ok with changes.

[eileenmcnaughton]

I'm merging this as it is a reviewer's commit by @monishdeb & the original submitter @sunilpawar has confirmed the changes - @sunilpawar if you haven't retested it would be good if you could double check on master once this is merged or commit to testing on the rc when it is cut at the start of Jan