Splits the insights page into separate sections with their own separate
filters. Each filter is sticky to the top of the page, similar to how
the previous filters worked.
In doing this, I have also moved around a lot of code. Refer to the
inline comments for more specific examples, but on a high level, this
PR:
- Moves the flag check from InsightsCharts into Insights itself. Because
the old Insights had filters and state, and the new one does not, it
made sense to fork off higher up in the tree. Because the new version
doesn't have state, I have also simplified it and removed an
intermediate component (InsightsCharts) that doesn't feel necessary
anymore.
- Because InsightsCharts isn't used anymore, I've moved the
LegacyInsightsCharts file back into InsightsCharts. However, I'm happy
to move it back if we think that's useful.
- Instead of all charts living in InsightsCharts, I've split each
section into its own file in the new sections directory. Because the
sections have separate filters, they don't share any state anymore, so
there's nothing they share.
- I'm reusing the existing hook and endpoint. As it stands, the
performance insights use **most** of the data from that payload (but not
all of it). The user insights use some of it. Flag lifecycle insights
doesn't use anything, but I've wired it up to make the filters work. I
expect that we'll iterate on the API endpoints etc later.

We're migrating to ESM, which will allow us to import the latest
versions of our dependencies.
Co-Authored-By: Christopher Kolstad <chriswk@getunleash.io>
This change specifies the update type as `replace` for the
`useQueryParams` hook used to set table state.
Primarily, this prevents the column selection from being added to the
browser
history and more importantly prevents you from changing your config by
navigating through browser history.
However, this also affects other table state, such as changing sorting
order etc. These will also no longer be added to the browser history.
---
Bug description:
In the project flag table, you can select which env columns to show.
However, adding and removing these envs get added as steps in your
browser history. This means that if you add 3 envs, you:
1. have to go back three times to get back to the previous page
2. In doing so, you also inadvertently revert the choices you mean,
which can be confusing.
Steps to reproduce:
1. Navigate to the project screen
2. Use the column selector to add/remove projects. Notice that the URL
changes for each selection you make.
3. After making one or more changes, use the browser's
back-functionality. Notice that you stay on the same page but that the
selected envs (and the URL) change.