Get correct Flash mode via API

[Jason2866]

Flash Mode is not read from magic header.
Th PR includes #7159

Fixes #7140

[Jason2866]

Output of test sketch

I (41) spi_flash: detected chip: gd
I (50) spi_flash: flash io: qio
I (50) coexist: coexist rom version e7ae62f
I (50) cpu_start: Starting scheduleESP32 SDK: v4.4.3-167-ge53afc285c
ESP32 DEVICE: ESP32-S3
ESP32 CPU FREQ: 240 MHz
ESP32 XTAL FREQ: 40 MHz
ESP32 APB FREQ: 80.0 MHz
ESP32 FLASH SIZE: 8.00 MB
ESP32 FLASH MODE: QIO
ESP32 RAM SIZE: 400.06 KB
ESP32 FREE RAM: 376.41 KB
ESP32 MAX RAM ALLOC: 343.99 KB
ESP32 FREE PSRAM: 7139.33 KB

[me-no-dev]

I think you have mixed the code from both PRs here. Please fix that. Also, why remove the enum and replace it with string? Please revert that and provide another method do get the string.

p.s. Question how that will behave on OPI stands here as well.

[Jason2866]

Will not open a new PR before #7159 is included in some way.
Can not test OPI, since no device.