Improve identifier restrictions

We cleaned up old Wasp DSL Analyzer code in #4797 and I noticed that our identifier validation could be improved.

Some rules don't make sense anymore, like rejecting from, while names like class pass but can break generated code e.g.

export const class = createJobDefinition(...)

Let's check where we output these names and what restrictions we actually need. In some places we could change the generated code, e.g. use obj["name"] instead of using name directly to avoid the need to restrict the names.

Related: #284