Bug loading peak_range files

[fanchercm]

Describe the bug

• Saving the peak range after fitting results in a plain text file instead of a .json; attempting to load the .json crashes the program
• Changing the extension to .json and loading also crashes the program

I've included these files titled "peak_range" in /SNS/user/bwing/data/HFIR/HB2B/IPTS-33202/shared/analysis/bjw

To Reproduce
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Expected behavior
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Environment (please complete the following information):

• OS: [e.g. Ubuntu]
• Version [e.g. 22]

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