[credential-providers]: add fromStatic credential provider

[trivikr]

Describe the feature

Add fromStatic credential provider which returns the static credentials passed to it.

Use Case

There's a static credential provider in v2, called AWS.Credentials.

An equivalent in v3 does not exist.

The v3 does have a static token provider though.

Proposed Solution

Add static credential provider, say fromStatic in @aws-sdk/credential-providers

Example usage:

import { fromStatic } from "@aws-sdk/credential-providers";

const creds = fromStatic({
  accessKeyId: 'akid',
  secretAccessKey: 'secret',
  sessionToken: 'session',
})

Other Information

Example use in production https://github.com/ToolJet/ToolJet/blob/bea8d1bd25075503e0873ddc74a0b271be1ce071/plugins/packages/amazonses/lib/index.ts#L80-L87

Acknowledgements

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

SDK version used

main

Environment details (OS name and version, etc.)

N/A