[refactor] Replace manual semantic version utilities/functions with semver package (#5653)

## Summary
- Replace custom `compareVersions()` with `semver.compare()`
- Replace custom `isSemVer()` with `semver.valid()`  
- Remove deprecated version comparison functions from `formatUtil.ts`
- Update all version comparison logic across components and stores
- Fix tests to use semver mocking instead of formatUtil mocking

## Benefits
- **Industry standard**: Uses well-maintained, battle-tested `semver`
package
- **Better reliability**: Handles edge cases more robustly than custom
implementation
- **Consistent behavior**: All version comparisons now use the same
underlying logic
- **Type safety**: Better TypeScript support with proper semver types


Fixes #4787

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-5653-refactor-Replace-manual-semantic-version-utilities-functions-with-semver-package-2736d73d365081fb8498ee11cbcc10e2)
by [Unito](https://www.unito.io)

---------

Co-authored-by: DrJKL <DrJKL@users.noreply.github.com>
Co-authored-by: Claude <noreply@anthropic.com>

src/components/dialog/content/MissingCoreNodesMessage.vue

@@ -43,11 +43,11 @@
 
 <script setup lang="ts">
 import Message from 'primevue/message'
+import { compare } from 'semver'
 import { computed } from 'vue'
 
 import type { LGraphNode } from '@/lib/litegraph/src/litegraph'
 import { useSystemStatsStore } from '@/stores/systemStatsStore'
-import { compareVersions } from '@/utils/formatUtil'
 
 const props = defineProps<{
   missingCoreNodes: Record<string, LGraphNode[]>
@@ -68,7 +68,7 @@ const currentComfyUIVersion = computed<string | null>(() => {
 const sortedMissingCoreNodes = computed(() => {
   return Object.entries(props.missingCoreNodes).sort(([a], [b]) => {
     // Sort by version in descending order (newest first)
-    return compareVersions(b, a) // Reversed for descending order
+    return compare(b, a) // Reversed for descending order
   })
 })