Add NVS component, wrapping esp-idf nvs_handle.hpp

[SamAtBackbone]

Some convenience wrappers for reaching the NVS on ESP. Usable with any namespace and variable.

Description

Created an API including calls to:

• Init
• Erase
• Get variables
• Set variables

with the ESP NVS system.

Created an example app to test and show the API.

Note that Namespace and Key must be <=15 characters because of the underlying system. This would previously cause a panic abort, so we're testing for string length in this API

Motivation and Context

Convenience wrappers of all the tests etc required to interface to the NVS

How has this been tested?

Running both my own app that uses this class, and the example app included.

Screenshots (if appropriate, e.g. schematic, board, console logs, lab pictures):

Example app running and being reset via button:

If namespace or key is too long:

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [X] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [X] Documentation Update
• [ ] Hardware (schematic, board, system design) change
• [ ] Software change

Checklist:

• [X] My change requires a change to the documentation.
• [ ] I have added / updated the documentation related to this change via either README or WIKI

[github-actions[bot]]

:white_check_mark:Static analysis result - no issues found! :white_check_mark: