This commit collects many changes to limit the public interface,
align with Java standards, align with idioms from the rest of the
Smithy codebase, and generally clean up the codebase.

Several packages, classes, and methods have been removed, renamed,
moved, or changed visibility. Use of `assert` has been removed and
the usage of `stream` has been reduced. Classes with multiple subtypes
have had their subtype names adjusted for compatibility with Java and
been broken out to their own packages and classes.

This commit removes the custom validation system that required code
to validate a ruleset and its tests, integrating the validation with
Smithy's built in ModelValidation system. Several bugs in validators
and test cases were fixed. Test cases were moved to using the standard
errorfiles based setup where applicable.

Some related refactoring was also performed.

This commit adds validation that for every endpoint test case that
contains operationInputs, the operation input entries match their
specified operation's input structure.

Co-authored-by: Russell Cohen <[email protected]>

This commit collects many changes to limit the public interface,
align with Java standards, align with idioms from the rest of the
Smithy codebase, and generally clean up the codebase.

Several packages, classes, and methods have been removed, renamed,
moved, or changed visibility. Direct access to inner mutable types
has been removed. The internal complexity of the CoverageChecker
has been significantly reduced while maintaining used functionality.

This commit refactors the configuration and inheritance hierarchy
of functions in the rules engine. Two intermediate abstract classes
have been eliminated, SingleArgFunction and Function.

All functions are now supplied through an SPI on FunctionDefinition,
and each implementation now supplies a FunctionDefinition. Special
cases for methods when generating from FunctionNode instances have
also been removed, aligning all implementations to the same
construction. No behavior has changed in the ExpressionVisitor to
reduce the impact of migration.

Unused, or minimally test-case used, convenience functions have been
removed.

Several bugs were fixed, including dropping context information from
certain sets of RulesError generation.

This commit pulls the AWS specific rules engine functions into a new
package, smithy-aws-rules-engine. This includes parseArn, partition,
and isVirtualHostableS3Bucket. The partition loading has also moved
to this package, including its data types.

Relevant tests were migrated. Behavior that was only possible to
validate using the parseArn function have been moved, even if the
behavior is not AWS specific. Tests that used AWS functions but did
not require it were updated to be agnostic.

This commit updates the endpoint rule set SPI to provide several
components to the implementation, built-in parameters and auth
scheme validators in addition to library functions. AWS specific
components have been extracted to their own package, and core
components are provided through their own extension.

Add the `disableNormalizePath` property as an allowed property for
sigv4 and sigv4a auth schemes. This parameter is required for some
services (eg: S3) to correctly sign requests. Specifying it in
endpoint parameters will allow SDKs to potentially remove more S3
customizations.

Co-authored-by: Alex Woods <[email protected]>

This commit adds a ModelTransformerPlugin implementation that removes
test case entries that rely on operations being removed from a model.
If all test cases are removed, the trait is also removed.

Updates the loading of the EndpointRuleSetExtension SPI to use a lazy
instance holder that is loaded when referenced instead of a lock-based
static initializer. The APIs that access the holder are labeled internal,
as the access patterns may change if the content needs to vary by
instance of the EndpointRuleSet.

* Add defaultGlobalRegion to partitions output

* Rename default to implicit

* Remove optional

This commit adds a `SyntaxElement` abstract class that contains several
methods intended for use in constructing rule-sets in code. This class
implements two new interfaces (`ToCondition` and `ToExpression`) to support
converting between types of syntax elements that compose into rule-sets.
The `Condition`, `Parameter`, and `Expression` classes extend this,
allowing all types of ruleset syntax to be composed this way.