[Feat-1081] Render empty state explorer (no resources)

[umrkhn]

Fixes: #1081

Problem

Explorer page renders an empty canvas when there are no resources.

Solution

The Explorer page should render an EmptyState component when there are no resources available.

Changes Made

• added an asset purplin/devops.svg.
• added support for the devops svg in the EmptyState component.
• rendered the EmptyState component when there are no resources on the explorer page
• fixed a small className typo in /components/explorer/DependencyGraph.tsx

Checklist

• Code follows the contributing guidelines
• Changes have been thoroughly tested
• Documentation has been updated, if necessary
• Any dependencies have been added to the project, if necessary

Reviewers

[umrkhn]

Sorry I was busy didn't update my PR but thanks @mlabouardy for resolving the conflicts. Although there was still one change I had to do will update in my next PR.