Improve extension properties template selection

[Heorhi Davydau (TechOctopus)]

Updated the extension properties template to align with YouTrack documentation:

• Added support for the primitive type float, which was previously missing.
• Enabled selection of any available YouTrack entity as a type.
• Replaced the "select" input with "autocomplete" for easier searching and selection.
• Restricted the "Is it a set of values?" option to non-primitive types, as per documentation.
• Expanded "What is the target extending entity?" to include all YouTrack entities.