[Lens] Treemap error on sparse table

[dej611]

Describe the bug:

In some specific scenarios the Treemap throws a Maximum stack error. Note that Treemap is the only partition visualization type affected by this issue.

Steps to reproduce:

1. Create a Lens visualization from the Flight sample data
2. Define a Group by dimension as Date histogram with timestamp
3. Define a Metric dimension as Count of Records
4. Define the time range to 15 minutes

Expected behavior:

The Treemap renders.

Screenshots (if relevant):

Errors in browser console (if relevant):

Uncaught RangeError: Maximum call stack size exceeded
    at bestVector (treemap.js:39:1)
    at treemap (treemap.js:76:1)
    at treemap (treemap.js:98:1)
    at treemap (treemap.js:98:1)
    at treemap (treemap.js:98:1)
    at treemap (treemap.js:98:1)
    at treemap (treemap.js:98:1)
    at treemap (treemap.js:98:1)
    at treemap (treemap.js:98:1)
    at treemap (treemap.js:98:1)

[elasticmachine]

Pinging @elastic/kibana-visualizations @elastic/kibana-visualizations-external (Team:Visualizations)