Major update

[gdbarron]

• Fix Comments still reference deleted function Get-ServiceNowUser #239
• Add How to Modify Custom Variables for RITMs or Requested Items #237
• Fix Error with v3.4.3 #234
• Fix Zero size files cause 'Bad Request' error #241
• Get-ServiceNowRecord -New has been deprecated and the new format is the only option
• Update-ServiceNowChangeRequest, Update-ServiceNowincident, and Update-ServiceNowRequestedItem deprecated. Use Update-ServiceNowRecord. The only difference was the table name and didn't make sense to maintain so many functions when documenting will do. Update-ServiceNowRecord has been enhanced as well so all updates can take advantage.
• Get-ServiceNowRecordInterim has been deprecated.
• Add generic -Table and -ID lookup function has been created and used across all functions where these parameters are used
• Add -Table tab ahead for Remove-ServiceNowRecord and Export-ServiceNowRecord
• Add -ID only lookup, no table name needed, for all
• Add/Update parameter sets to make it clearer when to use -Table, -ID, -Filter, etc
• Add New-ServiceNowChangeRequest support for change models and standard change templates
• Add pipeline support to Export-ServiceNowRecord, New-ServiceNowRecord, and Update-ServiceNowRecord
• Add Get-ServiceNowRecord -ParentID without providing -Table returns all tasks associated with that parent record
• Standardize parameter names across functions
• Add Update-ServiceNowRecord -CustomVariableData to update custom variable values