Feature/v2/all tools sidebar (#4151)

# Description of Changes

- Added the all tools sidebar
- Added a TextFit component that shrinks text to fit containers
- Added a TopToolIcon on the nav, that animates down to give users
feedback on what tool is selected
- Added the baseToolRegistry, to replace the old pattern of listing
tools, allowing us to clean up the ToolRegistry code
- Fixed Mantine light/dark theme race condition 
- General styling tweaks

---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

frontend/src/components/tools/shared/NoToolsFound.tsx

@@ -0,0 +1,15 @@
+import React from 'react';
+import { Text } from '@mantine/core';
+import { useTranslation } from 'react-i18next';
+
+const NoToolsFound: React.FC = () => {
+  const { t } = useTranslation();
+  
+  return (
+    <Text c="dimmed" size="sm" p="sm">
+      {t("toolPicker.noToolsFound", "No tools found")}
+    </Text>
+  );
+};
+
+export default NoToolsFound;

frontend/src/components/tools/shared/SubcategoryHeader.tsx

@@ -0,0 +1,17 @@
+import React from 'react';
+
+interface SubcategoryHeaderProps {
+  label: string;
+  mt?: string | number;
+  mb?: string | number;
+}
+
+export const SubcategoryHeader: React.FC<SubcategoryHeaderProps> = ({ label, mt = '1rem', mb = '0.25rem' }) => (
+  <div className="tool-subcategory-row" style={{ marginLeft: '1rem', marginRight: '1rem', marginTop: mt, marginBottom: mb }}>
+    <div className="tool-subcategory-row-rule" />
+    <span className="tool-subcategory-row-title">{label}</span>
+    <div className="tool-subcategory-row-rule" />
+  </div>
+);
+
+export default SubcategoryHeader;