Implement expression functions

[SteveL-MSFT]

Summary of the new feature / enhancement

ARM has a specific set of functions that can be used within a configuration: https://learn.microsoft.com/en-us/azure/azure-resource-manager/templates/template-functions

Proposed technical implementation details (optional)

Array

• [ ] array
• [x] concat
• [ ] contains
• [x] createArray
• [ ] empty
• [ ] first
• [ ] indexOf
• [ ] intersection
• [ ] last
• [ ] lastIndexOf
• [ ] length
• [ ] min
• [ ] max
• [ ] range
• [ ] skip
• [ ] take
• [ ] union

CIDR

These aren't relevant to DSC

Comparison

• [ ] coalesce
• [ ] equals
• [ ] less
• [ ] lessOrEquals
• [ ] greater
• [ ] greaterOrEquals

Date

• [ ] dateTimeAdd
• [ ] dateTimeFromEpoch
• [ ] dateTimeToEpoch
• [ ] utcNow

Deployment

• [ ] deployment?
• [ ] environment*
• [x] parameters*
• [x] variables*

Logical

• [ ] and
• [ ] bool
• [ ] false
• [ ] if
• [ ] not
• [ ] or
• [ ] true

Numeric

• [x] add
• [ ] copyIndex
• [x] div
• [ ] float
• [x] int
• [x] min
• [x] max
• [x] mod
• [x] mul
• [x] sub

Object

• [ ] contains
• [ ] createObject
• [ ] empty
• [ ] intersection
• [ ] items
• [ ] json
• [ ] length
• [ ] null
• [ ] union

Resource

Subset needed for DSC

• [x] reference*
• [ ] references
• [x] resourceId

Scope

Not applicable to DSC

String

• [x] base64
• [ ] base64ToJson
• [ ] base64ToString
• [x] concat
• [ ] contains
• [ ] dataUri
• [ ] dataUriToString
• [ ] empty
• [ ] endsWith
• [ ] first
• [ ] format
• [ ] guid
• [ ] indexOf
• [ ] join
• [ ] last
• [ ] lastIndexOf
• [ ] length
• [ ] newGuid
• [ ] padLeft
• [ ] replace
• [ ] skip
• [ ] split
• [ ] startsWith
• [ ] string
• [ ] substring
• [ ] take
• [ ] toLower
• [ ] toUpper
• [ ] trim
• [ ] uniqueString
• [ ] uri
• [ ] uriComponent
• [ ] uriComponentToString