refactor: Introduce 'DateTime/' sub-directories in 'src/' and 'tests/'

[claremacrae]

Types of changes

Internal changes:

• Refactor (prefix: refactor - non-breaking change which only improves the design or structure of existing code, and making no changes to its external behaviour)

Description

Move all date utility code to:

• src/DateTime/
• tests/DateTime/

Motivation and Context

To aid discoverability and reusability of existing code, and prepare for implementing a date-picker tool.

How has this been tested?

• Existing automated tests.

Checklist

• My code follows the code style of this project and passes yarn run lint.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• My change has adequate Unit Test coverage.

Terms

• My contribution follows this project's contributing guide
• I agree to follow this project's Code of Conduct

[sonarqubecloud]

Quality Gate passed

Issues
14 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud