x11/contour: Fix build with libunicode-contour 0.8.0

x11/contour: Bump port revision after libunicode-contour shlib version bump
(742f17431143)

x11/contour: Unbreak build on -CURRENT

clang with debug assertions enabled (on -CURRENT) crashes when it
tries to compile this port. As a workaround use clang from ports when
system clang has debug assertions enabled.

x11/contour: Replace patch for crispy::fnv with upstreamed one

x11/contour: Update to 0.6.2.8008

While here, add patch to fix build with clang/libc++ 19.

libc++ 19 only provides std::char_traits for character types, which
causes compile errors when crispy::fnv is instantiated with non-char
types.

Restricting string-related overloads to char-only types, and adding a
generic trivially-copyable value hashing overload restore successful
builds on clang/libc++ 19.

Changelog: https://github.com/contour-terminal/contour/releases/tag/v0.6.2.8008

Reported by:	portscout

x11/contour: fix build on powerpc*

Workaround for clang crash:
Assertion failed: (isValid()), function getFilename, file
/usr/src/contrib/llvm-project/clang/include/clang/Basic/SourceLocation.h, line
328.

x11/contour: Bump port revision after libunicode-contour shlib version bump
(a7befa6f427c)

x11/contour: bump port revision after libunicode-contour shlib installation path
change

x11/contour: use CMAKE_TESTING_ON to build unit tests instead of CMAKE_ON

Don't force everyone to build unit tests. Move devel/catch2 to test
dependency as it is only needed for testing only not build.

Reported by:	diizzy (via ports-committers)

x11/contour: add port: Modern C++ terminal emulator

Contour is modern, fast, and designed for everyday use. It's not just
a terminal emulator, but a powerhouse of features tailored for those
who seek efficiency and control. With GPU-accelerated rendering and
high-DPI support, experience the smoothest and most responsive
terminal emulator like never before.

WWW: https://contour-terminal.org/