build: rename CMake find modules for LibFindMacros #10928

We are using "LIBFOO" prefixes for `LIBFOO_INCLUDE_DIRS` etc, and
therefore need to use this for the PREFIX with LibFindMacros also, so
that `"${${PREFIX}_FIND_VERSION}"` gets handled there properly.

The alternative would be to either manually handle/set the upper/mixed case
variants of those variable additionally, which is not as easy.

Keeping the existing names is useful for packagers.

Before this the version requirements with
`find_package(Unibilium 2.0 REQUIRED)` was not handled (a49cf5126), and
it prepares for using a required version with libvterm
(initially/wrongly ported in 1896c72a5).

CMakeLists.txt

@@ -408,7 +408,7 @@ endif()
 option(FEAT_TUI "Enable the Terminal UI" ON)
 
 if(FEAT_TUI)
-  find_package(Unibilium 2.0 REQUIRED)
+  find_package(UNIBILIUM 2.0 REQUIRED)
   include_directories(SYSTEM ${UNIBILIUM_INCLUDE_DIRS})
 
   list(APPEND CMAKE_REQUIRED_INCLUDES "${UNIBILIUM_INCLUDE_DIRS}")
@@ -432,7 +432,7 @@ if(FEAT_TUI)
   include_directories(SYSTEM ${LIBTERMKEY_INCLUDE_DIRS})
 endif()
 
-find_package(LibVterm REQUIRED)
+find_package(LIBVTERM REQUIRED)
 include_directories(SYSTEM ${LIBVTERM_INCLUDE_DIRS})
 
 if(WIN32)