refactor(editor): unify directories naming (#11516)

**Directory Structure Changes**

- Renamed multiple block-related directories by removing the "block-" prefix:
  - `block-attachment` → `attachment`
  - `block-bookmark` → `bookmark`
  - `block-callout` → `callout`
  - `block-code` → `code`
  - `block-data-view` → `data-view`
  - `block-database` → `database`
  - `block-divider` → `divider`
  - `block-edgeless-text` → `edgeless-text`
  - `block-embed` → `embed`

blocksuite/affine/blocks/divider/src/styles.ts

@@ -0,0 +1,19 @@
+import { css } from 'lit';
+
+export const dividerBlockStyles = css`
+  .affine-divider-block-container {
+    position: relative;
+    width: 100%;
+    height: 1px;
+    display: flex;
+    flex-direction: column;
+    justify-content: center;
+    padding: 18px 8px;
+    margin-top: var(--affine-paragraph-space);
+  }
+  .affine-divider-block-container hr {
+    border: none;
+    border-top: 1px solid var(--affine-divider-color);
+    width: 100%;
+  }
+`;