Turn AssetInventory sub-plugin into a Security solution page (#205363)

## Summary

Turn AssetInventory plugin into a simple Security solution page based on
this conversation:
- https://github.com/elastic/security-team/issues/10346

Follow-up of this work, where we initially developed the Asset Inventory
bare-bones as a plugin:
- https://github.com/elastic/kibana/issues/201704

Part of this work stream though not originally planned:
- https://github.com/elastic/security-team/issues/11247?reload=1

### Motivation

Reasoning behind is enabling fast development changes without any major
refactors in other packages/components that need to be reused, which
seems impossible as of now with the current codebase.

### Checklist

- [x] If a plugin configuration key changed, check if it needs to be
allowlisted in the cloud and added to the [docker
list](https://github.com/elastic/kibana/blob/main/src/dev/build/tasks/os_packages/docker_generator/resources/base/bin/kibana-docker)
- [x] This was checked for breaking HTTP API changes, and any breaking
changes have been approved by the breaking-change committee. The
`release_note:breaking` label should be applied in these situations.
- [x] The PR description includes the appropriate Release Notes section,
and the correct `release_note:*` label is applied per the
[guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

### Identify risks

In the future, we'll probably have to turn AssetInventory into a
sub-plugin again. Doing so doesn't bring any risk in the present, and
should only involve the re-generation of the deleted files in this PR.

---------

Co-authored-by: Paulo Henrique <paulo.henrique@elastic.co>
Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

docs/developer/plugin-list.asciidoc

@@ -467,10 +467,6 @@ The plugin exposes the static DefaultEditorController class to consume.
 |WARNING: Missing README.
 
 
-|{kib-repo}blob/{branch}/x-pack/solutions/security/plugins/asset_inventory/README.md[assetInventory]
-|Centralized asset inventory experience within the Elastic Security solution. A central place for users to view and manage all their assets from different environments.
-
-
 |{kib-repo}blob/{branch}/x-pack/platform/plugins/private/banners/README.md[banners]
 |Allow to add a header banner that will be displayed on every page of the Kibana application