Updating icu4c in OpenJFX:

1) Update the modules/javafx.web/src/main/legal/icu_web.md LICENSE file.
Update the version at the top. Copy the license from icu4c/LICENSE.
Update modules/javafx.web/src/main/native/Source/ThirdParty/icu/LICENSE as well.

2) Copy the files from common, i18n, stubdata and tools/toolutil directories.
Remove Makefile.in files.

3) Update modules/javafx.web/src/main/native/Source/ThirdParty/icu/CMakeLists.txt.
Update ICU_*_SOURCES using sources.txt file.
Set ICU_DATA_FILE_NAME variable to the correct icudt*l.dat file.

4) Update the ICU version in build.gradle.

5) Expand tabs and remove trailing white spaces from source files.

6) Verification: FX sdk build and all test run, on all supported platforms.
