[Ref] improve readability of acl code

[eileenmcnaughton]

Overview

Code readability tidy up

Before

Variables ($acl & $cg2) used for table names in the sql

After

aliases assigned in mysql & used for table names in the sql

Technical Details

Variables are used in this code for table names, making the queries hard to read.

Since there is quite a bit I've only tackled 2 patterns

1. using where an alias within mysql would do
2. using where an alias within mysql would do

Ideally we want to switch to using CRM_Core_DAO::executeQuery & ditch the variables for
table names altogether but since there is a lot I've stuck to one pattern for this change

Comments

[civibot]

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[eileenmcnaughton]

@seamuslee001 wanna check this - it passes tests & I tried to limit the change so it would be an easy merge

[yashodha]

@eileenmcnaughton The pattern seems to be repeated on https://github.com/civicrm/civicrm-core/blob/master/CRM/ACL/BAO/ACL.php#L360 as well. Are you planning on making changes in other places as well?

[eileenmcnaughton]

@yashodha yes - if this gets merged I'll chip away further at the readability of the class

[yashodha]

@eileenmcnaughton looks good to me

[eileenmcnaughton]

@yashodha please merge it if you have reviewed it

[yashodha]

@eileenmcnaughton merging this