Don't show slider fill before value equal to initial value

[evansjohnson]

Fixes https://github.com/palantir/blueprint/issues/6844

Checklist

• [x] Includes tests
• [n/a] Update documentation

Changes proposed in this pull request:

I can't think of a reason a user would want the track to be filled from min to value when value === initial value, but then have value to initial value filled when value is just slightly less.

I imagine this case just wasn't explicitly considered, since often min may equal initial value and this issue is not apparent.

Reviewers should focus on:

If there's any valid use case for this track fill behavior.

Screenshot

Issue observable on slider example if showing fill for bottom example

[svc-palantir-github]

don't show slider fill before value equal to initial value

Build artifact links for this commit: documentation | landing | table | demo

This is an automated comment from the deploy-preview CircleCI job.