fix(BaseViewer): swap canvas and project logo

[nikku]

Proposed Changes

Ensures that the canvas is first in the focus / accessibility hierarchy of the browser:

Without the fix the browser would tab through the diagram like this:

bpmn.io logo
canvas

Checklist

To ensure you provided everything we need to look at your PR:

• Brief textual description of the changes present
• Visual demo attached
• Steps to try out present, i.e. using the @bpmn-io/sr tool
• Related issue linked via Closes {LINK_TO_ISSUE} or Related to {LINK_TO_ISSUE}

[abdul99ahad]

I couldn't focus the canvas. Is there something I'm missing testing this?

[nikku]

@abdul99ahad did you npm install before? Canvas focus is only added in recent versions of the library.