Tockloader

- Add `--jlink-serial-number` and `--openocd-serial-number` to specify which board to use if multiple are connected.
- Add `tockloader install --layout` to enable specifying the location and padding when installing apps. This is useful for debugging different application layouts with the kernel.
- Add boards:
- `opentitan_earlgrey_rom_ext`
- `veer_el2_sim`
- Add `tockloader list --map` that shows a memory-map view of installed apps.
- Add support for signing TBFs with ECDSA signatures.

This release improves Tockloader support on Windows.

Other improvements:
- Autodiscover the nrf52840dk on openocd.
- ShortId TBF header.
- Autodiscover the VCOM0 port on the nrf52840dk for `tockloader listen`.

- Improve command line help
- Update STM boards
- Add requirements.txt
- Use nrf52840 for jlink rather than nrf52

Changes in this release:
- Support reading kernel attributes to detect where application RAM starts.
- Skip sending empty pages in the serial bootloader connection.
- Update menus for interactive options.
- Better understand app RAM addresses when installing fixed address apps.

This release includes general improvements to Tockloader. The two main changes are:

- Add support for credentials. There is a new command `tockloader tbf credential` which allows for creating, viewing, verifying, and removing credentials for a TAB.
- Add support for TicKV. Tockloader can now query a tickv key-value store, and add/remove objects.

In this release:

- Added SMA Q3 and QEMU RISC-V 32 bit "virt" boards
- OpenOCD fixes and updates
- Added `Display` class for doing machine readable output in JSON format
- Added interactive selection menu instead of having to enter a number to choose the architecture to inspect