Breaking change: Field types incodersdk.UpdateTemplateMeta forIcon,Description, andDisplayName moved to*string

Summary

In this pull request we're updating theUpdateTemplateMeta struct to allowDisplayName,Description, andIcon to be set as empty"" or default to the value from the template if not provided in an update call.

Fixes#19036

The bug

The reported bug occurred when clients were attempting to update a metadata field in a template via an edit call. When the request was decoded into anUpdateTemplateMeta struct the default values for fields in the struct were used to update the template even if they weren't provided. This led to fields likeIcon being set to"" (the default value).

Changes

To allow for specific fields to be set to"" these fields were updated to be*string as opposed tostring. This allows for clients to set these fields as"" in an update request or they will default to the template value if they are not provided in the update request (will benil).

Added tests to confirm empty and nil values and updated other tests that use these fields.