Refactor course instance table to obtain the default list of columns
from a state value rather than a hard-coded list of columns

The lack of a "meetings" column in the default view meant that the
meeting modal integration tests were failing as they were expecting an
"Edit Meeting" button to be visible. Since the meetings column was not
visible, this was not the case and the tests thusly failed.

This commit adds the meetings column into the default view to fix these
breaking tests

Going by the previous course planner, `notes` is an optional column

Since this expression just returns an array, we don't need the spread operator
here

Other pages (such as `FacultyAdmin` and `CourseAdmin`) all use the
`VerticalSpace` component for providing vertical space around the page
content

Aside from being deprecated in later versions(
testing-library/dom-testing-library#416) it's also
not needed here, as we can just return `findByDisplayValue` directly

The type can automatically be inferred from `defaultView` and usage of
`T as Type` can actually interfere with other type checking done by
TypeScript.