Fix: Vue3: Installed extensions throw unhandled exception

[aalves08]

Summary

Fixes #11695

Occurred changes and/or fixed issues

• Add missing connection in vue.config to allow population of process.env.UI_EXTENSIONS_API_VERSION variable
• Add proxy for /version endpoint in vue.config
• Remove duplicated mechanism of error display in slide-in extensions panel for details PluginInfoPanel
• Add default fallback for ui-extensions-version annotation to be >= 3.0.0
• Make watches in uniplugins/index.vue as deep: true in order to reconnect proper triggers for reload banner and status update that were lost with the Vue3 migration
• Remove “duplicate” check for kube version that wasn’t preventing loading of extension but simply informing the user that it wasn’t compatible in uniplugins/index.vue
• Move /rancherversion network request to shell/plugins/plugin where loading order for extensions in order to correctly populate the rancher version for shouldNotLoadPlugin check
• Add /version network request to shell/plugins/plugin in order to correctly populate the kube version for shouldNotLoadPlugin check

Technical notes summary

Areas or cases that should be tested

• Load an extension with the required API version >= 3.0.0
• Load an extension with the required API version >= 2.0.0
• Load an extension without the catalog.cattle.io/ui-extensions-version annotation

Areas which could experience regressions

Screenshot/Video

Deprecated error banner in slide-in panel

Output of /version endpoint

**Error display with loading prevented - shouldNotLoadPlugin check **

Warning display when there's a newer version of an extension BUT it's not compatible

Checklist

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