feat(msc_host): Add format MSC support

[igi540]

Requirements

Provide the possibility to format connected flash drive

Description

Currently the flash drive should be formatted in advance, otherwise it can be formatted by ESP when mount error is present. To have the possibility to format connected flash drives in the USB Host MSC class driver explicitly, the new API call has been added. Now, the format process of the flash drive can be done not only during the mounting failure (format_if_mount_failed and FR_NO_FILESYSTEM) but explicitly from the application logic.

Related

• Closes Missing option for USB MSC drive format (IDFGH-14076) esp-idf#14890
• IDFGH-14076 Missing option for USB MSC drive format

Testing

Added test case for testing public API.

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Checklist

Before submitting a Pull Request, please ensure the following:

• 🚨 This PR does not introduce breaking changes.
• All CI checks (GH Actions) pass.
• Documentation is updated as needed.
• Tests are updated or added as necessary.
• Code is well-commented, especially in complex areas.
• Git history is clean — commits are squashed to the minimum necessary.

[roma-jam]

Just two small nitpicks, otherwise LGTM.

UPD: two small nitpicks about the code itself.

Couple of notes regarding the PR itself:

• Usually we squash the commit history to make the PR more precise and not flood commit history with the commits. It could be done before merging and PR could have several commits, if the PR is complex enough and need to be reviewed in several steps (like this one: USB Host UVC driver version 2 #84)
• PR description. Here I just prefer to reflect all the things that could help myself to understand why I did that commit (for me in the future). So, usually, I have:
  • Requirements section. This is a small info, which helps us to answer the question "why I am doing that?" or "why do we need that?" For example: Provide the possibility to format connected flash drive
  • Description section. This is a bit deeper description of the changes in the PR. Like, some technically related note, reasons or general description of the changes. Or might be the part of the issue description. For example: Currently the flash drive should be formatted in advance, otherwise it can be formatted by ESP when mount error is present. To have the possibility to format connected flash drives in the USB Host MSC class driver explicitly, the new API call has been added. Now, the format process of the flash drive can be done not only during the mounting failure (format_if_mount_failed and FR_NO_FILESYSTEM) but explicitly from the application logic.
  • Related section. Here we could have all related tickets. For example: - Closes https://github.com/espressif/esp-idf/issues/14890

Other fields are optional and may be added or kept clean.
It is not that strict as we have them in GitLab, but I thing that general idea to have the description here and there as close to each other as possible will help us.

[peter-marcisovsky]

We can also update our tests, and use this new function.

Here, we have test case called can_be_formatted where we force fail mounting of the partition, to trigger the formatting.

Thus, we could either use this new public API function, to format the partition in this existing test case, instead of force failing the mounting.

Or to create a new, similar test case, where we create a file, format the partition and check if the file exists.

Otherwise LGTM

[igi540]

@peter-marcisovsky ok, thank you for suggesting about adding test case. I added another test case. While updating test I found a line which I am not sure whether it is correct. Why does it erase memory before formatting? PTAL