Function to create identity authentication header

[Ethlas]

Desired Outcome

*Creating a module to be able to run a command that creates an authentication header for Identity ISPSS to later be used in other scripts

Implemented Changes

Describe how the desired outcome above has been achieved with this PR. In particular, consider:

• _What's changed? Added a module that has get-identityheader function in it
• How should the reviewer approach this PR, especially if manual tests are required? Run the script and see if an authentication token is being created

Should look like this:

Name                           Value
----                           -----
X-IDAP-NATIVE-CLIENT           true
Authorization                  Bearer eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCIsImtpZCI6IjQ5REJCQjc

• Are there relevant screenshots you can add to the PR description?

Connected Issue/Story

Definition of Done

At least 1 todo must be completed in the sections below for the PR to be merged.

Changelog

• [ ] The CHANGELOG has been updated, or
• [ ] This PR does not include user-facing changes and doesn't require a CHANGELOG update

Test coverage

• [ ] This PR includes new unit and integration tests to go with the code changes, or
• [ ] The changes in this PR do not require tests

Documentation

• [ ] Docs (e.g. READMEs) were updated in this PR
• [ ] A follow-up issue to update official docs has been filed here: [insert issue ID]()
• [ ] This PR does not require updating any documentation

Behavior

• [ ] This PR changes product behavior and has been reviewed by a PO, or
• [ ] These changes are part of a larger initiative that will be reviewed later, or
• [ ] No behavior was changed with this PR

Security

• [ ] Security architect has reviewed the changes in this PR,
• [ ] These changes are part of a larger initiative with a separate security review, or
• [ ] There are no security aspects to these changes