Optimize ParameterAsString

[danielmarbach]

For now I continue a bit on the path to use ValueStringBuilder where StringBuilders are used. There is probably even more room for optimizations but it seems a low effort way to get some gains

Description

Motivation and Context

https://github.com/danielmarbach/aws-sdk-net-benchmarks/blob/main/ParameterAsString.cs

Testing

I have added a test that verifies the current functionality works and then applied the optimizations which still pass the same test

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have read the README document
• I have added tests to cover my changes
• All new and existing tests passed

License

• I confirm that this pull request can be released under the Apache 2 license

[danielmarbach]

I will add a test to check the before and after

[danielmarbach]

@normj @dscpinheiro this is ready

[danielmarbach]

FYI I will be going on vacation end of this week and probably become unresponsive for at least three weeks