Sh/parse cdata

[shetzel]

What does this PR do?

Allows metadata files containing CDATA to be deployed.

What issues does this PR fix or reference?

forcedotcom/cli#1467
@W-10946208@

[WillieRuemmele]

QA:
Before:

Type   Name          Problem
─────  ────────────  ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
Error  CustomLabels  Error parsing file: Unexpected element {http://soap.sforce.com/2006/04/metadata}p during simple type deserialization (8:19)

ERROR running force:source:deploy:  Deploy failed.

AFTER:
✅ : source:deploy
✅ : source:retrieve
✅ : source:pull
✅ : source:push
✅ : source:convert -> mdapi:beta:deploy