Themes 1986: Add Alt tags to images where missing

[nschubach]

Description

Jira Ticket: THEMES-1986

Adding alt tags to images where they were not previously (as necessary)

Test Steps

1. Checkout this branch git checkout themes-1986
2. Run fusion repo with linked blocks npx fusion start -f -l
3. Verify that the medium and small top table list promos have alt values: http://localhost/pagebuilder/editor/curate?p=puOvG1XS6AaSAy1u&v=vy3r49MKAaSAy1u
4. Verify that the alt property is applied to the search-results-list, results-list, numbered-list, and simple list where the header is NOT enabled in the block config: http://localhost/pagebuilder/editor/curate?p=pldHYSIJj7fEkicu&v=vOlaaYHh67fEkicu

[vgalatro]

Had a bunch of docker issues trying to get my local env up and running, but once it was everything here looked good. Approved!