Add tooltips to detail page section titles and metrics

[justinanderson]

There should be tooltips on the detail page for section titles and metrics when tooltips are defined in the layout response. Note that no tooltip content exists as of yet, so some lorem ipsum gibberish or other placeholder should be used for now.

For example, if the detail layout returned in http://localhost:8000/datasets/small-business-support/ looks like:

"detailLayout":
{
  ...
  "sections":
  [
    ...
    {
      "title": "Economy",
      "tooltip": "Income and employment of workers in South Australia.\n\nSource: Australian Bureau of Statistics",
      "metrics":
      [
        {
          "title": "Income Gini Coefficient",
          "tooltip": "A common measurement of economic inequality within a region. A Gini coefficient of 0.0 implies an equal distribution of income among all workers in the region. A coefficient of 1.0 implies all of the region's income is concentrated in just a few workers."
        },
        ...
      ]
    },
    ...
  ]
}

Then the detail page should have an InfoOutlinedIcon <IconButton> appended after the "Economy" section title and after the "Income Gini Coefficient" metric title. When an info icon is clicked, it should show its tooltip content in a MUI Tooltip. An info icon should default to the color hsl(0,0%,70%) and, when hovered, be hsl(0,0%,40%). Sections and metrics without a defined tooltip should not have any icon.

So, the above might end up looking like: