UI Accessibility - Page, header, and image titles and text

[Worfle]

From #196 ::

• [x] Dynamic page title
  • http://portal.demo.solo.io/apis/ - "E-commerce Portal - APIs"
  • http://portal.demo.solo.io/apis/gloo-system/petstore?v=v1 - "E-commerce Portal - petstore v1"
  • http://portal.demo.solo.io/apis/gloo-system/petstore?v=checked - "E-commerce Portal - petstore checked"
  • http://portal.demo.solo.io/keys/ - "E-commerce Portal - API Keys"
• [x] Alt text for all images and SVGs
• [x] Missing headings
  • All pages need at least 1 <h1> tag, we can swap whatever div contains the page title to use a h1

[Worfle]

To add context, @kcbabo and @williamgrh , I'm reading these and seeing this set as solely relevant to PortalUI. Altering page title and forcing h1s in seem odd in an app the style of Admin, but I can if we need (may need to discuss the < h1 > concept)

I'm adding the text for images/svgs to Admin as well, as it's just good practice.

[kcbabo]

Primary focus here was the dev portal UI, so approach sounds good to me.