KRACOEUS-7296:Create Proposal Submit Panel

Submitting pull request after discussing with Gayathri.
I'd rather view only related methods like this be put on the viewhelperservice instead. They can be accessed using SpEL similar to the following.

```
@{!#ViewHelper.isAttachmentEditable(#collectionGroup.bindingInfo.bindingPath,#index,editableAttachments)}
```