Validate input yaml

[lrobion]

Draft to start work on #99, all tests in test_yamlreader.cpp

• YAML reader checks for input keys that do not exist in default and errors out, tested in TEST_CASE("Validate Input Files")
• YAML reader checks that input keys have the same structure as default: a value node in the default is also a value node in the override, a map node in default is also a map node in override. Currently a menu with something like "SIMULATION MENU: 4" can overwrite the entire simulation menu with a value when that node should hold a map to the submenus. Tested in TEST_CASE("Validate Input Files")
• YAML reader checks for inputs that are duplicated in the same file, tested in TEST_CASE("Validate Input Files")
• YAML reader correctly merges the same key (currently they get appended but the correct one is returned by the operator[] lookup because it returns the first). This is not an issue currently, but might be when we dump the finalized YAML. Tested in TEST_CASE("mergeYamlNodes keeps each key exactly once")
• YAML reader rejects non scalar keys: APCEMM does not use them, and this simplifies parsing logic, tested in TEST_CASE("mergeYamlNodes rejects non-scalar keys")
• Fix defaults in advanced menu being set in readAdvancedMenu instead of in defaults/input.yaml
• Ensure CMake re-generates the includable files when they are modified (before if you modified defaults/input.yaml and ran the build, the default values would not have been updated because this is done at the configure step)
• Remove SampleRunDir/ which has been superseded by examples/issl_rhi140/ (it cannot run without an input met.nc and there is no reason to maintain it anymore)
• Remove unused yaml test file

APCEMM now throws more helpful error messages for bad YAML files:

• For a duplicated key in the same YAML: Invalid field in YAML input file '/home/louis/code/APCEMM/examples/issl_rhi140/example.yaml': Duplicate key found: 'PARAMETER MENU -> METEOROLOGICAL PARAMETERS SUBMENU -> Pressure [hPa] (double)'. Each key must appear only once. Group all the entries of a menu under a single heading.
• Finding a key in a user input that does not exist in the default field: Invalid field in YAML input file '/home/louis/code/APCEMM/examples/issl_rhi140/example.yaml': Unknown key found: 'PARAMETER MENU -> METEOROLOGICAL PARAMETERS SUBMENU -> Unsupported field'

[lrobion]

Moving these goals as another PR to make it easier to review:

• YAML reader does not accept Monte Carlo / sweep style inputs anymore
• All inputs in default/input.yaml have been verified to be parsed and act on the code
• YAML reader dumps a finalized YAML that is exactly what APCEMM will use
• Get rid of all custom string parsing and use YAML tools (blocked by sweep style inputs)