utf8proc: add run_tests.sh

[DavidKorczynski]

run_tests.sh is used as part of Chronos with cached builds: https://github.com/google/oss-fuzz/tree/master/infra/experimental/chronos#check-tests

$ infra/experimental/chronos/check_tests.sh utf8proc c++
...
...
Running tests...
Test project /src/utf8proc/build
      Start  1: utf8proc.testcase
 1/10 Test  #1: utf8proc.testcase ................   Passed    0.07 sec
      Start  2: utf8proc.testcustom
 2/10 Test  #2: utf8proc.testcustom ..............   Passed    0.01 sec
      Start  3: utf8proc.testiterate
 3/10 Test  #3: utf8proc.testiterate .............   Passed    0.01 sec
      Start  4: utf8proc.testmisc
 4/10 Test  #4: utf8proc.testmisc ................   Passed    0.01 sec
      Start  5: utf8proc.testprintproperty
 5/10 Test  #5: utf8proc.testprintproperty .......   Passed    0.00 sec
      Start  6: utf8proc.testvalid
 6/10 Test  #6: utf8proc.testvalid ...............   Passed    0.01 sec
      Start  7: utf8proc.testmaxdecomposition
 7/10 Test  #7: utf8proc.testmaxdecomposition ....   Passed    0.03 sec
      Start  8: utf8proc.testcharwidth
 8/10 Test  #8: utf8proc.testcharwidth ...........   Passed    0.09 sec
      Start  9: utf8proc.testgraphemetest
 9/10 Test  #9: utf8proc.testgraphemetest ........   Passed    0.01 sec
      Start 10: utf8proc.testnormtest
10/10 Test #10: utf8proc.testnormtest ............   Passed    0.35 sec

100% tests passed, 0 tests failed out of 10

Total Test time (real) =   0.58 sec