Add loading spinner SVG

[kgcreative]

Description

• add loading spinner svg and remove horizontal bar loading indicator

Issues Resolved

solves line item: OpenSearch mark loading spinner in #372

Check List

• New functionality includes testing.
  • All tests pass
• New functionality has been documented.
  • New functionality has javadoc added
• Commits are signed per the DCO using --signoff

[opensearch-ci-bot]

❌   DCO Check Failed 20f9c8d
Run ./dev-tools/signoff-check.sh remotes/origin/main 20f9c8d978c2746988d6f2f2e82c94538a593c84 to check locally
Use git commit with -s to add 'Signed-of-by: {EMAIL}' on impacted commits

[opensearch-ci-bot]

❌   DCO Check Failed 3105bbe
Run ./dev-tools/signoff-check.sh remotes/origin/main 3105bbe1179e847889e2ccd03b60f6091d85d1e2 to check locally
Use git commit with -s to add 'Signed-of-by: {EMAIL}' on impacted commits

[mihirsoni]

@kgcreative Could you sign your commits ?

[kgcreative]

@kgcreative Could you sign your commits ?

Yep - I might close this PR and open a new one because I somehow messed up the rebase on local (yay git)

[opensearch-ci-bot]

❌   DCO Check Failed f490899
Run ./dev-tools/signoff-check.sh remotes/origin/main f49089901023293cae4725463762884ff26f4078 to check locally
Use git commit with -s to add 'Signed-of-by: {EMAIL}' on impacted commits

[kgcreative]

Closing PR -- will open new one, properly signed.

New PR: #387