Replace .my.cnf with column-statistics.cnf at the system level for mysqldump

[misilot]

Fixes #10176

Replace .my.cnf with column-statistics.cnf at the system level for mysqldump

The column-statistics.cnf file is copied to /etc/mysql/conf.d/column-statistics.cnf for each Dockerfile that exists.

This puts it as a system level mysql client change, so the web ui interface also works.

Description

Adds a mysql configuration file that disables column-statistics for mysqldump, which allows the snipe-it backup to run as expected. As well as the web ui for making backups, as pointed out by @aduzsardi

Fixes # 10176

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Try running backup from existing container, to a mysql 5.x database server. It fails. Add the column-statistics.cnf to /etc/mysql/conf.d/column-statistics.cnf with the following contents:

[mysqldump]
column-statistics=0

Run backup from web ui.

Checklist:

• I have read the Contributing documentation available here: https://snipe-it.readme.io/docs/contributing-overview
• I have formatted this PR according to the project guidelines: https://snipe-it.readme.io/docs/contributing-overview#pull-request-guidelines
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes