LIMS-1390: Fix searching of data collection groups

[ndg63276]

JIRA ticket: LIMS-1390

Summary:

Viewing a data collection group (or a group linked by a processing job) and then using the search box gives a server error.

Changes:

• Remove unnecessary lower() and concat() calls as MariaDB is case-insensitive and you can pass many arguments to a single concat()
• Add to $where2, $where3 and $where4 rather than replacing them, as the $args array has already been populated expecting them to have several extra values

To test:

• Go to a data collection group, eg /dc/visit/mx34566-20/dcg/12631761 and search for just one of the data collections, eg 16_1, and check only one data collection is shown
• Go to a data processing group eg /dc/pjid/24527370, and search for just one of the data collections, eg 12_1, and check only one data collection is shown
• Go to a full visit eg /dc/visit/mx34566-20 and check the search box works as expected