refactor(editor): rename doc to store on block components (#12173)

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->

## Summary by CodeRabbit

- **Refactor**
  - Unified internal data access by replacing all references from `doc` to `store` across all components, blocks, widgets, and utilities. This affects how readonly state, block operations, and service retrieval are handled throughout the application.
- **Tests**
  - Updated all test utilities and test cases to use `store` instead of `doc` for document-related operations.
- **Chores**
  - Updated context providers and property names to reflect the change from `doc` to `store` for improved consistency and maintainability.

No user-facing features or behaviors have changed.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/shared/src/commands/block-crud/get-first-content-block.ts

@@ -23,7 +23,7 @@ export const getFirstBlockCommand: Command<
     firstBlock: BlockModel | null;
   }
 > = (ctx, next) => {
-  const root = ctx.root || ctx.std.host.doc.root;
+  const root = ctx.root || ctx.std.host.store.root;
   if (!root) {
     next({
       firstBlock: null,

blocksuite/affine/shared/src/commands/block-crud/get-last-content-block.ts

@@ -23,7 +23,7 @@ export const getLastBlockCommand: Command<
     lastBlock: BlockModel | null;
   }
 > = (ctx, next) => {
-  const root = ctx.root || ctx.std.host.doc.root;
+  const root = ctx.root || ctx.std.host.store.root;
   if (!root) {
     next({
       lastBlock: null,