Remove tooltips from labels of tabular chart legends

This issue is a follow-up of this discussion: !1385 (comment 343613592)

Summary:

Outside of what I assume is a small % of use cases where the label name is really, really long, they aren't really helping users. In fact, it feels like they are creating unnecessary noise. If the decision is between having them show in all circumstances or not have them at all, I'd probably opt to hide them completely.

Tooltip to be removed