feature: Add lead icon to task nodes

[jeff-phillips-18]

What

Closes #65

Description

Adds the ability to show a custom icon before the text in a pipeline TaskNode.

Type of change

• [x] Feature

Screen shots / Gifs for design review

[jeff-phillips-18]

Surge: https://topology-pipeline-icon.surge.sh/

[github-actions[bot]]

:tada: This PR is included in version 5.0.0-alpha.2 :tada:

The release is available on:

• GitHub release
• npm package (@alpha dist-tag)

Your semantic-release bot :package::rocket:

[github-actions[bot]]

:tada: This PR is included in version 5.0.0-prerelease.1 :tada:

The release is available on:

• GitHub release
• npm package (@prerelease dist-tag)

Your semantic-release bot :package::rocket: