Add title attribute support to <img> tag in Drimage template

Problem/Motivation

Drimage improved is missing the title attribute output for image fields.
This causes inconsistencies between Drimage improved and plain Drimage.

Steps to reproduce

• Add an image field to an entity.
• Set a title value for the image.
• View the rendered image on the site, the title attribute is missing from the <img> tag.

Proposed resolution

• Add logic to print the title attribute when present in the Drimage improved template.
• Approach is based on a similar fix in #3438094: Add title attribute on <img> tag.

<img src="{{ dummy_image }}" width="{{ width }}" height="{{ height }}" alt="{{ alt }}"{% if title %}title="{{ title }}"{% endif %} class="drimage-image" />

Remaining tasks

• ✅ File an issue
• ✅ Addition/Change/Update/Fix
• ✅ Testing to ensure no regression
• ➖ Automated unit testing coverage
• ➖ Automated functional testing coverage
• ➖ UX/UI designer responsibilities
• ➖ Readability
• ➖ Accessibility
• ➖ Performance
• ➖ Security
• ➖ Documentation
• ✅ Code review by maintainers
• ✅ Full testing and approval
• ✅ Credit contributors
• ✅ Review with the product owner
• ✅ Release notes snippet
• ✅ Release drimage_improved-1.0.9

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• Issue #3522562 by steve hanson: Added title attribute support to <img> tag in Drimage template