Add cancellation token and default timeout (20s) to service requests

[jramsay]

Fixes #

Changes proposed:

• add cancellation token to all tunnelManagementClient requests
• add default connection/service response timeouts
• add unit tests

Other Tasks:

• If you updated the Go SDK did you update the PackageVersion in tunnels.go
• [✅ ] If you updated the TS SDK did you update the dependencies in package.json for connections and management to require a dependency that is > the current published version(Found using npm view @microsoft/dev-tunnels-contracts). This will fix issues where yarn will pull the old version of packages and will cause mismatched dependencies. See example PR

[osortega]

Would it be better to handle request retries completely within the SDK if there is already a way to track a request done through the SSH session?
This way it would be a transparent implementation on the user side instead of implementing the same thing for every API.