Common DynamoDb Enhanced interface for "queryable"

### Describe the feature

A common interface for `DynamoDbTable` and `DynamoDbIndex` defining the `scan` and `query` methods.

### Use Case

I have some pipeline methods that build `QueryConditional`s, execute them, and unpack the results. Sometimes these queries are aimed at the base table, and sometimes at GSIs, depending on the sorting criteria. Currently, the table and index interfaces share no common base interface, resulting in code duplication.

### Proposed Solution

`DynamoDbTable`'s query and scan methods return `PageIterable`, which is a subtype of `DynamoDbIndex`'s return type of `SdkIterable>`. A common interface `DynamoDbQueryable` could be extended by both the table and index interfaces with no impact to existing code.

### Other Information

_No response_

### Acknowledgements

- [X] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

### AWS Java SDK version used

2.20.50

### JDK version used

openjdk version "17.0.6" 2023-01-17 OpenJDK Runtime Environment Temurin-17.0.6+10 (build 17.0.6+10) OpenJDK 64-Bit Server VM Temurin-17.0.6+10 (build 17.0.6+10, mixed mode, sharing)

### Operating System and version

Gentoo Linux