fix(richtext-lexical): ensure sub-fields have access to full document data in form state (#9869)

Fixes https://github.com/payloadcms/payload/issues/10940

This PR does the following:
- adds a `useDocumentForm` hook to access the document Form. Useful if
you are within a sub-Form
- ensure the `data` property passed to field conditions, read access
control, validation and filterOptions is always the top-level document
data. Previously, for fields within lexical blocks/links/upload, this
incorrectly was the lexical block-level data.
- adds a `blockData` property to hooks, field conditions,
read/update/create field access control, validation and filterOptions
for all fields. This allows you to access the data of the nearest parent
block, which is especially useful for lexical sub-fields. Users that
were previously depending on the incorrect behavior of the `data`
property in order to access the data of the lexical block can now switch
to the new `blockData` property

docs/admin/hooks.mdx

@@ -654,6 +654,26 @@ const ExampleCollection = {
   ]}
 />
 
+## useDocumentForm
+
+The `useDocumentForm` hook works the same way as the [useForm](#useform) hook, but it always gives you access to the top-level `Form` of a document. This is useful if you need to access the document's `Form` context from within a child  `Form`.
+
+An example where this could happen would be custom components within lexical blocks, as lexical blocks initialize their own child `Form`.
+
+```tsx
+'use client'
+
+import { useDocumentForm } from '@payloadcms/ui'
+
+const MyComponent: React.FC = () => {
+  const { fields: parentDocumentFields } = useDocumentForm()
+
+  return (
+    <p>The document's Form has ${Object.keys(parentDocumentFields).length} fields</p>
+  )
+}
+```
+
 ## useCollapsible
 
 The `useCollapsible` hook allows you to control parent collapsibles: