Make build generation more efficient

[AndreaLupo]

Now it takes a lot of time to create all the builds. They're required:

• when listing builds in the build page
• in the build detail

The approach should be:

1. create the builds statically and save them as a dependency of the project (this point is to be defined). This should be a map to have access to it through hash directly.
2. Get the list of builds' hashes
3. Store them into local storage (quite lighter than whole build objs)
4. Save the hash of this list in local storage too
5. Resolve the build through hash from the static map build

I cannot save directly the builds' list in local storage since it's too big (that's what she said). This way builds are created once and not everytime the user access the page.

[AndreaLupo]

It's already better, but it's not enough. Builds' page requires like 3 seconds to load on a fast connection. Also, the loading is at route change so it seems like nothing is happening