[BUG] Use self-hosted popper.js instead of the unpkg.com hosted JS.

[nateynateynate]

Describe the bug

As part of a recent CVE we're ensuring that no scripts are being loaded externally to the site from places like unpkg.com.

Currently the only instance of unpkg I could find was for popper.js. Let's take care of that first. Then we can comb through for any other instances of externally hosted JS.

Expected behavior

All javascript should be hosted locally.

Screenshots

"popperjs" being loaded from unpkg.com

To Reproduce

Use developer console to view 'network' tab to see the domain we're pulling from.

Additional Details

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Host/Environment (please complete the following information):

• OS: [e.g. iOS]
• Version [e.g. 22]

Additional context
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