Adds methods for iterating and visiting

[14NGiestas]

Hi

This pull request introduces new functionalities for iterating over and visiting datasets in HDF5 files, along with some minor fixes and improvements. The most important changes include the addition of iterate and visit procedures, updates to CMakeLists.txt to accommodate new source files, and corrections to existing error messages.

New functionalities:

• Added iterate and visit procedures to the h5fortran module for iterating over and visiting datasets in HDF5 files. (src/interface.f90, src/iterate.f90, src/visit.f90) [1] [2] [3] [4]

Build system updates:

• Updated CMakeLists.txt to include new source files iterate.f90 and visit.f90. (src/CMakeLists.txt)

Documentation updates:

• Added documentation for the new iterate and visit procedures in API.md. (API.md)

Minor fixes:

• Corrected spelling error in README.md from "impementation" to "implementation". (README.md)
• Fixed error messages related to dataset slicing and dimensions in utils.f90 and write.f90. (src/utils.f90, src/write.f90) [1] [2] [3]

Testing updates:

• Added new tests for iterate and visit procedures in CMakeLists.txt for tests. (test/CMakeLists.txt)