Add new CMake packaging options for skipping building various modules

Allows for skipping building tools, contrib, tests, man pages and HTML documentation.

Currently, when building libtiff, all tools, tests, man pages and HTML documentation pages are built in addition to the library itself.

This isn't necessarily something we want to do, for example when building libtiff in an internal build pipeline.

This merge request attempts to add the following CMake options to the build system: tools, contrib, man-docs, html-docs and tests.

For instance, if one wishes to build libtiff without all the goodies included on Windows:

cmake "Visual Studio 17 2022" -Dtools=OFF -Dman-docs=OFF -Dhtml-docs=OFF -Dcontrib=OFF -Dtests=OFF ..

is now possible with this merge request.

Some contributed modules have executables that are not built when not building tools, and conversely, some tests cannot run when tools are not built. However, the simple tests will still run even when building with tools disabled.