… by expressions (#1400)

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### What

This PR corrects an issue where model permissions are not applied to
models used via relationships in order by expressions.

### How

The permissions are now correctly read out of the GraphQL schema
annotations and applied it to the predicate inside the relationship path
in order by targets in `crates/graphql/ir/src/order_by.rs`.

Because there are now predicates inside order by expressions, the
execution pipeline had to be updated to handle evaluating remote
predicates inside order by expressions too.

The tests in
`crates/engine/tests/execute/models/select_many/order_by/relationships/`
have been updated to test applied model permissions affecting ordering.

V3_GIT_ORIGIN_REV_ID: 783c204c44099e5319580e51e7549527d7a56245

…n the connector does not support it (#1443)

### What
This PR blocks the usage of nested fields and nested relationships
(where a relationship starts from a nested object) in order_by clauses
when the connector does not support it.

NDC v0.1.x has a capability for ordering by nested fields, and does not
support ordering by nested relationships at all. NDC 0.2.0 adds support
(and a capability) for ordering by nested relationships.

It also blocks being able to configure non-scalar fields as orderable in
Model v1.

These new errors are only raised if the new OpenDD flags are set. The
compatibility date to enable these flags is currently unset, pending a
production release date.

Actual support for nested relationships in ordering was "accidentally"
added in #1400, when relationship paths in order by targets were
properly modelled and implemented.

### How

Two new flags were added to OpenDD to cover the two new breaking
changes: `require_nested_support_for_order_by_expressions` and
`disallow_model_v1_ordering_non_scalar_fields`.

Logic in `crates/metadata-resolve/src/stages/models/order_by.rs` was
refactored and enhanced to check compatibility of order by expressions
used in a model against the model's source data connector.

Metadata resolve tests have been updated to test nested relationships in
ordering, and new tests added to test the new errors. Some existing
tests needed fixing to comply with the new logic without raising
warnings.

A new `execute` test has been added to cover ordering by nested
relationships in
`crates/engine/tests/execute/models/select_many/order_by/nested_relationships/`.

V3_GIT_ORIGIN_REV_ID: 3f4e01cddbbd80c4f190260df56dbdb13d0a1253