fix(designer): Remove double quotes wrapping from uncasted single tokens in array editor

[shuktika12163]

• Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes/features)
• Docs have been added / updated (for bug fixes / features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
  Bug fix for file content showing as empty/corrupted in email: https://msazure.visualstudio.com/One/_workitems/edit/27221229/

• What is the current behavior? (You can also link to an open issue here)
  When user gets a file from OneDrive and sends an email with file content in attachments, current behavior wraps a single token in array editor in @{} (double quotes) which during runtime stringifies the output of the token.

Serialized array editor:

Code view:

Due to this, the inputs generated for ContentBytes for the send email action in OpenApi format are not correct (ContentBytes is supposed to be an object).

Current raw inputs sample:

"emailMessage/Attachments": [
      {
          "Name": "test.pdf",
          "ContentBytes": "JVBERi0xLj..."
      }
  ],

• What is the new behavior (if this is a feature change)?
  In array editor, if the token is a single token and not casted, double quotes wrapping the token will be removed if present.

Serialized array editor:

Code view without {}:

Expected/new raw inputs sample after the change:

"emailMessage/Attachments": [
      {
          "Name": "test.pdf",
          "ContentBytes": {
                "$content-type": "application/pdf",
                "$content": "JVBERi0xLjcN..."
            }
      }
  ],

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)
  No

• Please Include Screenshots or Videos of the intended change:
  Provided above