Dashboard viz title improvements/flexibility

**Is your feature request related to a problem? Please describe.**
Titles on charts on dashboards are very hard to read.

**Describe the solution you'd like**
At a minimum, it would be nice to increase the font size, and maybe the title within the tile. Even better, the user could define the title font size/location in the visualization settings.\

**How important is this feature to you?**
Not super important, but it seems like it would be a pretty small tweak to make a big improvement in dashboard presentation.

:arrow_down: Please click the :+1: reaction instead of leaving a `+1` or `update?` comment

The issue names no files, tests, or entry points. Start by locating dashboard chart title rendering and visualization settings, then clarify whether the goal is a larger default title or user-configurable font size and location; done means chart titles are more readable and the agreed settings work consistently.

Written by the indexing model from the issue text.