Global graphql type definition

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### Is your feature request related to a problem? Please describe.

I’m trying to create a DataLayer for ClickHouse and I find myself in a dilemma.
I could either define the functions `graphql_type/1` and `graphql_input_types/1` inside my type definition,
or avoid including anything related to GraphQL and let the user define that.

Currently, it’s possible to define `type` and `input_type` for each attribute of a resource,
but it can get a bit tedious if you have many tables and fields of the same type.

```elixir
extensions: [AshGraphql.Resource]

graphql do
type :my_clickhouse_resource

attribute_types [
ch_datetime64_column_1: :datetime,
ch_datetime64_column_2: :datetime
]

attribute_input_types [
ch_datetime64_column_1: :datetime,
ch_datetime64_column_2: :datetime
]
end
```

### Describe the solution you'd like

So I wanted to know if it would be possible to add a global configuration
that works for all attributes of that type.

Something like this:

```elixir
extensions: [AshGraphql.Domain]

graphql do
attribute_types [
{AshClickhouse.Type.ChDateTime64, :datetime}
]

attribute_input_types [
{AshClickhouse.Type.ChDateTime64, :datetime}
]
end
```

Or like this:
```elixir
config :ash_graphql,
attribute_types: [
{AshClickhouse.Type.ChDateTime64, :datetime}
],
attribute_input_types: [
{AshClickhouse.Type.ChDateTime64, :datetime}
]
```

I believe the ideal behavior would be for the configuration defined at the resource level
to override the global configuration.

### Describe alternatives you've considered

_No response_

### Additional context

_No response_

Start by tracing how the existing resource-level graphql attribute_types and attribute_input_types settings are read and applied. Determine where shared type mappings could be configured and how resource-level mappings should override them. Done means type-wide mappings work for both output and input types, with resource overrides covered by tests.

Written by the indexing model from the issue text.