feat: queriable / sortable / useAsTitle virtual fields linked with a relationship field (#11805)

This PR adds an ability to specify a virtual field in this way
```js
{
  slug: 'posts',
  fields: [
    {
      name: 'title',
      type: 'text',
      required: true,
    },
  ],
},
{
  slug: 'virtual-relations',
  fields: [
    {
      name: 'postTitle',
      type: 'text',
      virtual: 'post.title',
    },
    {
      name: 'post',
      type: 'relationship',
      relationTo: 'posts',
    },
  ],
},
```

Then, every time you query `virtual-relations`, `postTitle` will be
automatically populated (even if using `depth: 0`) on the db level. This
field also, unlike `virtual: true` is available for querying / sorting /
`useAsTitle`.

Also, the field can be deeply nested to 2 or more relationships, for
example:
```
{
  name: 'postCategoryTitle',
  type: 'text',
  virtual: 'post.category.title',
},
```

Where the current collection has `post` - a relationship to `posts`, the
collection `posts` has `category` that's a relationship to `categories`
and finally `categories` has `title`.

docs/configuration/overview.mdx

@@ -240,8 +240,8 @@ export default buildConfig({
   // highlight-start
   cors: {
     origins: ['http://localhost:3000'],
-    headers: ['x-custom-header']
-  }
+    headers: ['x-custom-header'],
+  },
   // highlight-end
 })
 ```

docs/fields/blocks.mdx

@@ -352,7 +352,7 @@ const config = buildConfig({
         },
       ],
     },
-     {
+    {
       slug: 'collection2',
       fields: [
         {
@@ -365,7 +365,7 @@ const config = buildConfig({
                 blocks: ['TextBlock'],
               }),
             ],
-          })
+          }),
         },
       ],
     },

docs/getting-started/installation.mdx

@@ -63,6 +63,7 @@ To install a Database Adapter, you can run **one** of the following commands:
   ```
 
 - To install the [Postgres Adapter](../database/postgres), run:
+
   ```bash
   pnpm i @payloadcms/db-postgres
   ```
@@ -80,7 +81,7 @@ To install a Database Adapter, you can run **one** of the following commands:
 
 #### 2. Copy Payload files into your Next.js app folder
 
-Payload installs directly in your Next.js `/app` folder, and you'll need to place some files into that folder for Payload to run. You can copy these files from the [Blank Template](https://github.com/payloadcms/payload/tree/main/templates/blank/src/app/(payload)) on GitHub. Once you have the required Payload files in place in your `/app` folder, you should have something like this:
+Payload installs directly in your Next.js `/app` folder, and you'll need to place some files into that folder for Payload to run. You can copy these files from the [Blank Template](<https://github.com/payloadcms/payload/tree/main/templates/blank/src/app/(payload)>) on GitHub. Once you have the required Payload files in place in your `/app` folder, you should have something like this:
 
 ```plaintext
 app/