Support user agent app tag in IMDS client

[croepha]

Describe the feature

I would like to be able to add some application specific string to the user agent header sent with http requests to the IMDS service

Use Case

This would be very helpful in debugging which application in an ec2 instance is making a request when viewing multiple requests in a packet capture. This could also be used to enhance auditing of IMDS requests

Proposed Solution

it seems that if you load a config with an option like config.WithAppID("myCoolApp") it does not actually effect the IMDS client. I think that you should make that config also apply to the IMDS client which would make the behavior the same as the majority of other clients in this package

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

AWS Go SDK V2 Module Versions Used

$ cat go.mod | grep aws
 github.com/aws/aws-sdk-go-v2 v1.32.6
 github.com/aws/aws-sdk-go-v2/config v1.28.6
 github.com/aws/aws-sdk-go-v2/credentials v1.17.47
 github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.16.21
 github.com/aws/aws-sdk-go-v2/service/firehose v1.35.2
 github.com/aws/aws-sdk-go-v2/service/kinesis v1.32.7
 github.com/aws/smithy-go v1.22.1
 github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.6.7 // indirect
 github.com/aws/aws-sdk-go-v2/internal/configsources v1.3.25 // indirect
 github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.6.25 // indirect
 github.com/aws/aws-sdk-go-v2/internal/ini v1.8.1 // indirect
 github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.12.1 // indirect
 github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.12.6 // indirect
 github.com/aws/aws-sdk-go-v2/service/sso v1.24.7 // indirect
 github.com/aws/aws-sdk-go-v2/service/ssooidc v1.28.6 // indirect
 github.com/aws/aws-sdk-go-v2/service/sts v1.33.2 // indirect

Go version used

go version go1.23.2 linux/amd64