Current conditions header

[eric-gade]

What does this PR do? 🛠️

Per one of the items in #516, the current conditions block does not have an h2 header. This prevents good screen reader navigation.

We have added the header -- and the config values that tell the block to display its label -- in this PR. Additionally, the header element has the usa-sr-only attribute, which means it will be invisible but will still be captured by the screen reader. We've done this in order to preserve the original design.

Screenshots (if appropriate): 📸

In this screenshot, you'll see the accessibility inspector highlighting an invisible element to the left (it's small). The inspector shows that it is a heading with the text Current conditions

[greg-does-weather]

Code Review Checklist

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The Basics

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• I read the code
• I ran the code
• (if applicable) Post deploy steps are run
• (if applicable) I validated the change on the deployed version in

Documentation

• changes to “how we do things” are documented in READMEs
• all new functions and methods are commented using plain language
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Security

• security false positives are documented
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Reliability

• error handling exists for unusual or missing values
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• functionality is tested with unit or integration tests
• dependency updates in composer.json also got changed in composer-lock.json

Infrastructure

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Accessibility

• New pages have been added to cypress-axe file so that they will be tested with our automated accessibility testing
• Meets WCAG 2.0 AA or 2.1 AA for Section 508 compliance
  • Site is keyboard accessible. All interactions can be accessed with a keyboard
  • Site is free of keyboard traps. The keyboard focus is never trapped in a loop
  • All form inputs have explicit labels
  • Form instructions are associated with inputs
  • All relevant images use an img tag
  • All images have appropriate alt attributes
  • Multimedia is tagged. All multimedia has appropriate captioning and audio description
  • Text has sufficient color contrast. All text has a contrast ratio of 4.5:1 with the background
  • Site never loses focus. Focus is always visible when moving through the page with the keyboard
  • Tab order is logical
  • Tables are coded properly. Tables have proper headers and column attributes
  • Headings are nested properly. Heading elements are nested in a logical way
  • Language is set. The language for the page is set
  • CSS is not required to use the page. The page makes sense with or without CSS
  • Links are unique and contextual. All links can be understood taken alone, e.g., ‘Read more - about 508’
  • Page titles are descriptive

Device Matrix

• firefox/gecko (renders correctly and user interactions work)
• chrome/chromium/edge (renders correctly and user interactions work)
• safari/webkit (renders correctly and user interactions work)
• web page is readable and usable
  • at 480px (mobile)
  • at 640px (tablet)
  • at 1024px (desktop)