Fix performance issues in table components

[maxatdetroit]

Describe the bug, To Reproduce, Expected behavior:

See CityOfDetroit/detroitmi#1392

Proposed Solution

Remove usage of nested, custom slot components in and child components, then reassess performance profile. Ultimately, the revised table should have an API similar to https://github.com/HTMLElements/smart-table.

If that doesn't achieve the performance we want, we'll have to take a closer look at some of the options in #170.

[maxatdetroit]

Capturing some notes here so I don't lose them:

When it comes to components with many, nested children that need to be styled, but whose content needs to remain in the lightDOM, our options are pretty limited. Good reading: https://is.gd/zAXxtA.

In short:

• We can't put all the children in a single slot because they won't receive styling from the shadow DOM.
• We can't remove slots entirely and put everything in the shadowDOM because then content won't receive lightDOM styling.
• We have to come up with some hybrid wherein most of the children are moved into the ShadowDOM and some are placed into slots (dynamically, not slotted by the user of the design system).