card10.cfg: Add config option for flashlight LED

See merge request !483

CTX Rendering

See merge request !473

"Cache" the local sleep value to not send repetitive sleep-out commands
to the display when the user repeatedly sets the backlight.

Adapted from previous implementation in !476.  To quote:

> This saves about 1 mA when the display is off.

Previously, such lines would be drawn as a fuzzy two-pixel wide line
instead of a sharp one-pixel one.  This is because the coordinate grid
is aligned _between_ pixels instead of on the pixel centers.  More
information in this cairo FAQ:

    https://www.cairographics.org/FAQ/#sharp_lines



For odd linewidths, add 0.5 to all coordinates to offset the line
perfectly onto the pixel grid.  This makes them look sharp, as with the
previous gfx code.

Suggested-by: Øyvind Kolås <pippin@gimp.org>

Not sure why I didn't do this right away, but using 1.95 makes the
circles look much better.  Using 2 leads to a small artifact on the
right side so we have to stay slightly below...

Remove the last remaining piece of gfx integration.  With this, the
card10 firmware is now fully rendering using ctx instead!

Reimplement `epic_disp_blit()` without relying on the gfx library.

Make the new ctx based implementation behave just like the old one.
This means _including_ the yend row and xend column.

This fixes the G-Watch and DigiClk not looking as they should.

Use ctx to display the panic message.  The implementation contains a few
safeguards to hopefully deal with any breakage that happended before the
panic.

With the PMIC task calling graphics code, it now needs a bit more stack
space.  Increase the allocation to ensure we won't get a stack overflow
here.

Instead of duplicating the drawing code in the personal state menu,
reuse the method from the parent class.  This reduces code duplication
but most importantly means the personal state app can benefit from fixes
in the "upstream" code.

Concretely, due to the changes related to ctx, this fixes visual
artifacts produced by the "custom" rendering code (black areas to the
right of the text).

Replace the gfx-based implementations of the Epicardium display API
calls with ctx-based ones that try to mimick the old behavior as much as
possible.  In the long run, these functions are just meant for backwards
compatibility while new code should interface with ctx directly (once
this becomes possible).

The implementations in this changeset are closely based on pippin's
original Pycardium display API reimplementation.

Co-developed-by: Øyvind Kolås <pippin@gimp.org>

Adds the most basic ctx integration, by just initializing the context
and nothing more.

From upstream commit 35100785e2c4 ("ctx: rasterizer, micro optimizations
in rasterizer_fill_rect").

The integration is mostly a copy of pippin's original integration with
the biggest change being the use of a monospace default font.  This font
is autogenerated from lib/ctx/fira-mono.ttf at build-time so it can be
easily replaced with a different one (just overwrite said file).

git-url: https://ctx.graphics/.git


Co-developed-by: Øyvind Kolås <pippin@gimp.org>

Move display initialization from hardware_early_init() into the display
module to keep it closer to related functionality.

Move the display API code into the display/ subdirectory as well.

To not try and replace the entire gfx stack at once, start by "splicing
in" the new driver for the two to work alongside each other.  Primarily
the new driver takes control now and we reconfigure the orientation on
the fly whenever the old driver wants to update the screen.

Currently we're still working with the reference driver from Waveshare.
This driver seems hacked together and also does not really fit for what
we're doing with the display.  Even less so because it configures the
display upside down.

As a first step towards dropping this vendor library, introduce
a reimplementation which is purpose built to our usecase.  This new
library configures the screen right side up natively but still allows to
change to the legacy orientation on the fly to support the old codebase.

Add a config option to indicate that a flashlight LED was soldered onto
the harmonic board.

Can be used to build docs and directly open them in the users default
web-browser:

	./Documentation/build-docs.sh --open

See merge request !481

ci: Expose artifacts for debug builds

See merge request !482

See merge request !478

See merge request !480

The loop condition in the epic_sleep based sleep could underflow if an
interrupt introduced too much delay at the end.

The clock source of epicardium is not very stable and can drift multiple
percent. This has an effect on epic_sleep() and can lead to sleeps which
are longer than anticipated. With this change we slowly move towards our
sleep goal using multiple calls. This is less efficient but leads to
precise results.