Update OpenSearch logos site-wide with new branding

[tmarkley]

Is your feature request related to a problem? Please describe.

OpenSearch Dashboards currently uses placeholder logos (e.g. "heatmap") that were set in the initial forking/renaming project: #37

Describe the solution you'd like

New icons/logos have been created for the public OpenSearch branding: https://opensearch.org/brand.html

All of the previous changes using the "heatmap" icon for OpenSearch and OpenSearch Dashboards need to be replaced with the updated logos.

Describe alternatives you've considered

N/A

Additional context

Commit to change logos for forking/renaming project: 905ccbe

Below are examples of the new marks/logos:

Default Mark

OpenSearch Dashboards Logo (Dark Mode)

[mihirsoni]

@tmarkley Would you be able to ensure you attach your PR to this issue ?

[tmarkley]

@tmarkley Would you be able to ensure you attach your PR to this issue ?

@mihirsoni Yep, I'm working on a draft now.