Update radio_bridge_packet_decoder.js

[megan-litterer]

Summary

The current radio bridge decoder handles thermocouple events as a uint16 when it is a signed 16 bit number per https://multitech.com/wp-content/uploads/S000826_Radio-Bridge-LoRaWAN-Wireless-Sensors_User-Guide.pdf.

This caused issues where negative numbers looked like large positive numbers.

Changes

I added proper handling for a signed 16 bit variable.

Checklist for Reviewers

• Title and description should be descriptive (Not just a serial number for example).
• profileIDs should not be vendorID and should be a unique value for every profile.
• All devices should be listed in the vendor's index.yaml file.
• Firmware versions can not be changed.
• At least 1 image per device and should be transparent.

Notes for Reviewers

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Release Notes

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[CLAassistant]

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