Make namespace max depth configurable in idGenerator

[rg911]

• Removed default namespace maxDepth.
• Removed namespace maxDepth validator from the sdk as it can be validated by the sever.
  Fixed namespace_max_depth should not be hardcoded #455

[fboucquez]

Users and model objects don't use IdGenerator directly. They go through NamespaceMosaicIdGenerator (for example NamespaceId).

The max depth default param value hides it from the main model objects so they ended up using the default value.

We can either:

1. Remove the default value and propagate maxDepth to the client objects.
2. Remove that validation to keep the API clean. Maybe provide a validate method after the namespace is created.

I don't particularly like either, do you have another option?

[rg911]

Users and model objects don't use IdGenerator directly. They go through NamespaceMosaicIdGenerator (for example NamespaceId).

The max depth default param value hides it from the main model objects so they ended up using the default value.

We can either:

1. Remove the default value and propagate maxDepth to the client objects.
2. Remove that validation to keep the API clean. Maybe provide a validate method after the namespace is created.

I don't particularly like either, do you have another option?

Discussed with @dgarcia360
maxDepth was hardcoded on the server previously but now made configurable. I have removed it and the validation to let the server validate the depth.