Extended & human-friendly keys

See the changelog additions for user-visible changes.

Since we enable/disable terminal protocols whenever we pass terminal ownership,
tests can no longer run in parallel on the same terminal.

For the same reason, readline shortcuts in the gdb REPL will not work anymore.
As a remedy, use gdbserver, or lobby for CSI u support in libreadline.

Add sleep to some tests, otherwise they fall (both in CI and locally).

There are two weird failures on FreeBSD remaining, disable them for now
https://github.com/fish-shell/fish-shell/pull/10359/checks?check_run_id=23330096362

Design and implementation borrows heavily from Kakoune.

In future, we should try to implement more of the kitty progressive
enhancements.

Closes #10359

cmake/Tests.cmake

@@ -1,13 +1,6 @@
 # This adds ctest support to the project
 enable_testing()
 
-# By default, ctest runs tests serially
-if(NOT CTEST_PARALLEL_LEVEL)
-  include(ProcessorCount)
-  ProcessorCount(CORES)
-  set(CTEST_PARALLEL_LEVEL ${CORES})
-endif()
-
 # Put in a tests folder to reduce the top level targets in IDEs.
 set(CMAKE_FOLDER tests)
 
@@ -24,8 +17,6 @@ set(SKIP_RETURN_CODE 125)
 #    running `make test` does not require any of the binaries to be built before testing.
 #  * The only way to have a test depend on a binary is to add a fake test with a name like
 #    "build_fish" that executes CMake recursively to build the `fish` target.
-#  * It is not possible to set top-level CTest options/settings such as CTEST_PARALLEL_LEVEL from
-#    within the CMake configuration file.
 #  * Circling back to the point about individual tests not being actual Makefile targets, CMake does
 #    not offer any way to execute a named test via the `make`/`ninja`/whatever interface; the only
 #    way to manually invoke test `foo` is to to manually run `ctest` and specify a regex matching
@@ -33,7 +24,7 @@ set(SKIP_RETURN_CODE 125)
 
 # The top-level test target is "fish_run_tests".
 add_custom_target(fish_run_tests
-  COMMAND env CTEST_PARALLEL_LEVEL=${CTEST_PARALLEL_LEVEL} FISH_FORCE_COLOR=1
+  COMMAND env FISH_FORCE_COLOR=1
           FISH_SOURCE_DIR=${CMAKE_SOURCE_DIR}
           ${CMAKE_CTEST_COMMAND} --force-new-ctest-process # --verbose
           --output-on-failure --progress