Add function to get aaasession

[overag3]

Description

Add function Get-NSAAASession to get NS AAA sessions.

With no parameter, all AAA sessions returned. The 'Username' and 'Filter' parameters can be used to select a specific session or a subset of sessions.

Motivation and Context

For some use cases, I need to retrieve the sessions to then manipulate them.

How Has This Been Tested?

$Hostname = 'hostname'
$Credential = Import-Clixml -Path .\cred.xml
$Session = Connect-NetScaler -Hostname $Hostname -Credential $Credential -Https -PassThru
$AAASessions = Get-NSAAASession -Session $Session
$AAAFilterSessions = Get-NSAAASession -Filter '^fr' -Session $Session
$AAAUserSessions = Get-NSAAASession -Name 'user1','user2' -Session $Session

$Users = 'user1', 'user2'
$Users | Get-NSAAASession -Session $Session

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 CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[overag3]

In my work env, all checks are passed, no problem detected.
Where is the mistake ?

Regards