tinyxml2 2.0.2 (new formula)

tinyxml2 is a light-weight c++ library for parsing xml. It
was previously submitted as a head-only formula in #23381
but was put on hold until releases could be tagged upstream.
The 2.0.2 release has just been tagged.

tinyxml2: add test that uses pkg-config to search for library

tinyxml2: add basic test for compiling and linking

Update tinyxml2.rb

Remove pkg-config test.
tinyxml2: add 2.0.2 bottle.

Closes #27622.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>