#### Tl;dr
Closes: enso-org/cloud-v2#1158
This PR adds a redirect to the stripe page where the user can manage his subscription
<details><summary>Demo Presentation</summary>
<p>
https://github.com/enso-org/enso/assets/61194245/360fdc7e-46ff-49fa-9936-e5c61fe6f917
</p>
</details>
---
#### Context:
Our first iteration was to add our billing page but after a few iterations, we decided to postpone it in favor of more important features.
#### This Change:
1. creates a link for a private user session
2. redirect the user to that page (open in a new tab) when the user clicks on the billing tab
#### Test Plan:
Go over how you plan to test it. Your test plan should be more thorough the riskier the change is. For major changes, I like to describe how I E2E tested it and will monitor the rollout.
---
- Remove unnecessary modules
- Remove `ts-plugin-namespace-auto-import` as it was a workaround to use the non-conventional `import *` convention
- Remove `esbuild-plugin-copy-directories` as it is unuse
- Inline modules that are only ever used once
- Inline `project-manager-shim` into `gui2` - it is only used during `gui2`'s dev mode
- Inline `content-config` into `client`
- Flatten `app/ide-desktop/lib/` to `app/ide-desktop/`
- Flatten `app/ide-desktop/lib/dashboard/` to `app/dashboard/`
# Important Notes
- As mentioned above, all remaining modules have been moved up from `app/ide-desktop/lib/` to `app/ide-desktop/`. It's not ideal but I'd rather hold off on moving them anywhere else before we have a consensus on what should go where.
- (That is to say, this may not be the final directory structure - but I figure it's fine to get *something* done so that hopefully the rest of the restructuring is simpler.)
