feat(core): support mentions in comments (#13000)

fix AF-2706, PD-2687

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

## Summary by CodeRabbit

* **New Features**
* Added support for mentions in comments and replies, including
detection and notification when users are mentioned.
* Introduced new notification types for comments and comment mentions,
with dedicated notification components and localized messages.
  * Enabled navigation directly to specific comments from notifications.
* Sidebar comment tab and comment features now depend on both feature
flags and server support.

* **Improvements**
  * Comment creation and reply workflows now support optional mentions.
* Menu configurations for linked widgets can now selectively include
specific menu groups.
* Enhanced navigation helper with a function to jump directly to a page
comment.
  * Improved comment entity lifecycle management for proper cleanup.

* **Bug Fixes**
* Improved lifecycle management for comment entities to ensure proper
cleanup.

* **Style**
* Updated mention styling to use a dynamic font size based on theme
variables.
  * Adjusted comment preview container underline highlight color.

* **Localization**
* Added English translations for comment and mention notification
messages.

* **Configuration**
* Updated feature flag logic for comment features, making configuration
more flexible and environment-aware.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->





#### PR Dependency Tree


* **PR #13000** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

blocksuite/affine/inlines/mention/src/affine-mention.ts

@@ -23,7 +23,7 @@ export class AffineMention extends SignalWatcher(
         'clig' off;
       /* Client/baseMedium */
       font-family: Inter;
-      font-size: 15px;
+      font-size: var(--affine-font-size-base);
       font-style: normal;
       font-weight: 500;
       line-height: 24px; /* 160% */