[H] Add safe type checking when processing inputs

[cleong14]

DoD: Sanitize prime-router/src/main/kotlin/transport/EmailTransport.kt input(s) and others impacted by ognl/thymeleaf.

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This is especially important when processing HTML text.

https://github.com/CDCgov/prime-reportstream/blob/f56ca7467198df84d225d7e58d00deb3a86097fc/prime-router/src/main/kotlin/transport/EmailTransport.kt#L67-L72

Relates to #18533

[megreed1]

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[jack-h-wang]

As stated in #18533 this change is not necessary from a security standpoint as the input for this function is system generated at run time without using external input.