Allow ~ in keys for escaped json pointer characters

[graytaylor0]

Description

Json pointer uses ~ character as the escape sequence in some places. For example, a literal / in the key name will be escaped with ~1, but Data Prepper JacksonEventKey is blocking this by not allowing ~ character

Issues Resolved

Resolves #5101

Check List

• [x] New functionality includes testing.
• [ ] New functionality has a documentation issue. Please link to it in this PR.
  • [ ] New functionality has javadoc added
• [x] Commits are signed with a real name per the DCO

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