v2: make resolved and forge schema similar

[lmolkova]

Extracted from #1106 (comment) -

Resolved schema v2 looks like this:

attribute_catalog
registry
  attributes
  attribute_groups
  spans
  metrics
  events
  entities
refinements
  ...

Materialized resolved (aka forge) schema v2 looks like this:

attributes
attribute_groups
signals
  spans
  metrics
  events
  entities
refinements  # same as resolved 
  ...

They describe the same thing in different ways and it makes sense to keep the difference between them to minimum.

the following proposal came up on the Weaver SIG:

attribute_catalog  # only in resolved
registry
  attributes
  attribute_groups
  spans
  metrics
  events
  entities
refinements

then the diff between schemas is minimal:

• attribute_catalog is only present in the resolved
• attributes are fully expanded in materialized one