removing restriction on dhw types

[ShiZhongming]

This PR is in line with #3400 This PR removes the restriction on creating user-defined HVAC DHW types. Users can rename existing DHW types or add new ones. The types are no longer restricted by the four types only (i.e., HVAC_HOTWATER_AS1, 2, 3 & 4)

How to test it?

navigate to >inputs>technology>assemblies>HVAC.xlsx>Tab HOT_WATER add one additional HAVC_HOTWATER type or making changes to an exisiting one navigate to >inputs>technology>archetypes>CONSTRUCTION_STANDARD.xlsx>TAB HVAC_ASSEMBLIES accordingly run energy demand simulation on a fresh scenario

[ShiZhongming]

The unit test database was not updated as the cea ch/sg database were both updated. Hence, locally on my computer, I executed create_unittest_datafirst and then the unit_testran through. However, still, this PR's Checks are all failed. @reyery any idea what's going on?

[reyery]

@ShiZhongming the test cases have been fixed. You can merge it.

[ShiZhongming]

Awesome! Thanks, @reyery.