customWorkspaces versions

Version has been removed from the workspaces and the issue now is that we can not specify version of customWorkspaces.

https://github.com/cheminfo/nmrium/blob/4ce0d2b363b73d561a0ba2e5810c84d28bedf341/src/demo/views/BenchtopNMRWorkspace.tsx#L305-L306

In order to get the version I guess the best is to change customWorkspaces properties to only accept array like:

```
[
{
version: 7, <-- NMRium version
name: 'My custom settings',
settings: {}, <-- the normal settings object without version
}
]
```

Likely that nobody is using this feature so we can make this change without any migration scripts. It is mainly our examples in this project that needs to be updated.