several link changes for doxygen and changes for deep links into doxygen itself

[lkurz]

Several links for doxygen need to be identified and changed:

1. https://hdfgroup.github.io/hdf5/v1_14//_h_d_f5_examples.html
   These links are for the github pages repo space which should not appear on support site or in documentation:

2. This is also an example of a deep link into the doxygen file structure.
   "_h_d_f5_examples.html"
   I think I know the answer is no or not yet. But are we using "anchors" in the doxygen code to which we can create deep and intelligible links into a doxygen space?

For Example
Suppose you have a function documented in Doxygen:
/// \anchor my_function
/// This is my function.
void myFunction();

In the external HTML page, you can link to this function using the tag file:
Link to myFunction

3. the following links to docs hdf5 directory point to https://docs.hdfgroup.org/releases/hdf5/latest-docs.html OR
   https://docs.hdfgroup.org/releases/hdf5/v1_14/v1_14_4/documentation/doxygen/index.html

http://docs.hdfgroup.org/hdf5/v1_14/index.html
http://docs.hdfgroup.org/hdf5/develop/index.html. < we actually don't want doxygen from develop branch on support site.

https://docs.hdfgroup.org/hdf5 should go away.

[lkurz]

The following files have many links to portal.hdfgroup.org/hdf5/ which is the develop branch github-pages build.
Currently these links are not failing, but should be changed to the proper intended doxygen release(s) for each file.

[lkurz]

Move issue to HDF5.