fix: drawing a single connecting line between points

[flekschas]

This PR ensures that a single line connecting all points is drawn correctly.

Description

What was changed in this pull request?

Previously, when one attempted to draw a single point connection that connects all points, no line would be drawn. This is now working.

As part of this fix, I also fixed the draw() functions resolution to await the drawing of point connections (when showPointConnections is set to true). Previously, draw() would resolve as soon as the points were drawn but drawing lines typically takes longer. Hence, draw() resolved too early. With this PR, when showPointConnections is true, draw() will resolve after both, the points and the connections, have been drawn.

Why is it necessary?

Fixes #125

Checklist

• Provided a concise title as a semantic commit message (e.g. "fix: correctly handle undefined properties")
• CHANGELOG.md updated
• Tests added or updated
• Documentation in README.md added or updated
• Example(s) added or updated
• Screenshot, gif, or video attached for visual changes