JUnit reporter className cpp to Java style namespace conversion

[Ext3h]

Describe the bug
A test of the form:

namespace foo { class bar {}; }
TEST_CASE_METHOD(foo::bar, "test")

using the junit reporter creates an output in the form

<testcase classname="test.exe.foo::bar" name="test" time="0.002" status="run"/>

The classname is mal-formed, a Java classpath like identifier was expected, but a C++ like class path is yielded instead.

Expected behavior

<testcase classname="test.exe.foo.bar" name="test" time="0.002" status="run"/>

The C++ style class path is translated properly into a Java style class path by substituting any :: in testInfo.className with ..

This allows Jenkins and Gitlab to properly group tests by namespace hierarchy as expected.