If there's only one device on the bus, the chip_select pin of the
peripheral can be fixed in hardware, therefore lowering the number of
pins required on the microcontroller side.
This patch allows this by making the chip_select pin optional.
This simplifies allocating outside of the VM because the VM doesn't
take up all remaining memory by default.
On ESP we delegate to the IDF for allocations. For all other ports,
we use TLSF to manage an outer "port" heap. The IDF uses TLSF
internally and we use their fork for the other ports.
This also removes the dynamic C stack sizing. It wasn't often used
and is not possible with a fixed outer heap.
Fixes#8512. Fixes#7334.
These are moved:
* Display -> busdisplay.BusDisplay
* FourWire -> fourwire.FourWire
* EPaperDisplay -> epaperdisplay.EPaperDisplay
* I2CDisplay -> i2cdisplaybus.I2CDisplayBus
`paralleldisplay` is now `paralleldisplaybus` (and registered as
`paralleldisplay` too).
Bus related helpers are split out of display_core into bus_core.
It is in still displayio since it is a dependency of both
busdisplay and epaperdisplay.
Fixes#7667
