toggle proper MER bits, taking in account dual bank mode enabled or not.

g4 cat3 devices can be configured in two mode via option bytes:
  - dual bank, 2x256kib, 2KiB pages.
  - single bank, 1x512KiB, 4KiB pages.
in anycase, these have two banks, and need to be handled with more care.

-> read optr after loading flash params to patch page size.
-> in single bank mode, mass erase _must_ be triggered by applying
MER1 and MER2 bits. erasing half of the flash will lead to a pgserr.

add a 'has_dual_bank' info to flash param, helping handling a couple of cases
 - selecting over dual bank specific code path without handling multiple chip id all over the code.
 - handling dual bank mode dynamic configuration

Update for STM32G471/473/474/483/484 devices

Fixed int length issues on 32-bit platforms.

(Closes #902)

- [doc] Updated list of supported devices
- [doc] verify udev-rules (Closes #764)
- Removed old issue-templates.
- Updated BSD-3 license file.

add usb pid for st-link v2.1, found on nucleo l432kc

- Whitespace cleanup
- Recycled content of old wiki page.

- Fixed formatting for options display.

- Resorted cmds to the order they appear.

- Updated "known missing features"
- Removed section "known bugs"

Note: Users should use the github ticket system to submit failures 
instead, otherwise they may not be fixed.

Closes #211 #782.
See also #733.

- Added note on correct libusb version.
- Formatting improvements
- Corrections to grammar and wording

make Version.cmake more error-resistant (Fixes #772)

Silence unnecessary messages (Fixes #240)

Error return in failed probe (Fixes #887)

check if app's need for libssp.

Added more error info to WLOGs during probe.

- Minor documentation fixes
- HOWTO and FAQ --> tutorial.md

Fixed wait-loop for flash_loader_run() & F72/F73 device description