Add docker container and compose file

[rtm516]

Description

Add a docker image that can be easily ran from GitHub container registry. Also fixes a few deprecation warnings from the use of htmlspecialchars.

It goes along with https://github.com/userjack6880/Open-Report-Parser/pull/19

Fixes #73

Re-created from https://github.com/userjack6880/Open-DMARC-Analyzer/pull/103 with a cleaner diff and corrected branch name

Type of change

Please delete options that are not relevant.

• [x] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

Test Configuration:

• OS: Rocky Linux 9.2
• OS Kernel Version:
• WebServer: Apache
• WebServer Version: 2.4 (inside the container)
• PHP Version: 8.2 (inside the container)
• SQL Variant: MySQL (MariaDB)
• SQL Version: 11.1.2 (also inside a container within the compose yml, not the one for this tool)

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [x] Any dependent changes have been merged and published in downstream modules
• [x] I have checked my code and corrected any misspellings

[sefasenturk95]

@userjack6880 Why hasn't this been checked/approved/merged yet?