Range-test: Clean on reboot

[ford-jones]

Resolves #7291
Extends the functionality of RangeTestModuleRadio with the ability to remove the rangetest.csv file generated by past range test usage. With the range_test.clear module configuration, previous range test results will be cleaned up after initialisation of the range test module / on reboot.

Ideally this could be toggled from the python CLI or with a UI component in the various clients - e.g. a button which changes the configuration option from true/false and vice versa.

I've made an accompanying pull request in protobufs which adds the option to the RangeTestConfig.

I'm a new contributor here so If any potential changes must be made let me know, I'm more than happy to oblige 🔧

This has been tested on two heltec v3 devices 👍

Testing method:

1. Ensure the device has a file located at /static/rangetest.csv by running the range test module on two nearby devices and navigating to http://meshtastic.local/rangetest.csv where the results will begin to download.
2. Pull protobuf changes from https://github.com/ford-jones/protobufs/tree/7291-rangeTest-clear
3. Run bin/regen-protos.sh
4. Enable the configuration option by uncommenting src/modules/RangeTestModule.cpp line 44
5. Build and flash changes to one of the devices
6. Enable the range test module, wait until your specified message interval has elapsed.
7. Attempt to download the csv file by navigating to http://meshtastic.local/rangetest.csv where the file will no longer be accessible.

🤝 Attestations

• I have tested that my proposed changes behave as described.
• I have tested that my proposed changes do not cause any obvious regressions on the following devices:
  • Heltec (Lora32) V3