Override smithy client retry config

[ymwjbxxq]

Motivation and Context

The current Retry logic is incorrect because the current behaviour is to generate random values before retrying, but other AWS SDK follow the rule:

• 100ms for all services
• 50ms for DynamoDB

awslabs/aws-sdk-rust#567

Description

• I changed the base to have a default of 100ms
• I exposed a method to overwrite the default value
• Calculating the backoff using the base of the configuration

Testing

1. Added integration test overriding the base value
2. Running all tests inside the rust-runtime/aws-smithy-client

All other commands in the readme like "./gradlew aws:rust-runtime:cargoTest" are failing with

./gradlew aws:rust-runtime:cargoTest

> Configure project :codegen-server-test
(scanned and found a Smithy CLI version 1.21.0. You will need to add an explicit dependency on smithy-model if publishing a JAR)

> Configure project :codegen-test
(scanned and found a Smithy CLI version 1.21.0. You will need to add an explicit dependency on smithy-model if publishing a JAR)

> Configure project :aws:sdk
(scanned and found a Smithy CLI version 1.21.0. You will need to add an explicit dependency on smithy-model if publishing a JAR)

> Configure project :aws:sdk-codegen-test
(scanned and found a Smithy CLI version 1.22.0. You will need to add an explicit dependency on smithy-model if publishing a JAR)

> Configure project :codegen-server-test:python
(scanned and found a Smithy CLI version 1.21.0. You will need to add an explicit dependency on smithy-model if publishing a JAR)

FAILURE: Build failed with an exception.

* What went wrong:
Task 'cargoTest' not found in project ':aws:rust-runtime'.

* Try:
> Run gradlew tasks to get a list of available tasks.
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.

* Get more help at https://help.gradle.org

Deprecated Gradle features were used in this build, making it incompatible with Gradle 8.0.

You can use '--warning-mode all' to show the individual deprecation warnings and determine if they come from your own scripts or plugins.

See https://docs.gradle.org/7.4.2/userguide/command_line_interface.html#sec:command_line_warnings

BUILD FAILED in 1s
9 actionable tasks: 9 up-to-date

Checklist

• [] I have updated CHANGELOG.next.toml if I made changes to the smithy-rs codegen or runtime crates
• I have updated CHANGELOG.next.toml if I made changes to the AWS SDK, generated SDK code, or SDK runtime crates

Help is needed

• to setup correctly the environment, I cannot make it with following the readme :(
• to understand how to move the changes into "/aws-sdk-rust/sdk/dynamodb/src)/config.rs", DynamoDB must be set with a base of 50ms for completetion.

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