Possible fix for #4485 (#4487)

* Possible fix for #4485

Throw's an exception when i is nullptr,
also added a testcase for this scenario though most likely in the wrong test file.cpp

* quick cleanup

* Fix compile issues

* moved tests around, changed exceptions, removed a possibly unneeded include

* add back include <memory> for testing something

* Ninja doesn't like not having a \n, at end of file, adding it back

* update input_adapter file to deal with empty/null file ptr.

* ran make pretty

* added test for inputadapter

* ran make amalgamate

* Update tests/src/unit-deserialization.cpp

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

* Update tests/src/unit-deserialization.cpp

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

* Update input adapters.hpp with new includes

* fix unabigious use of _, (there was a double declare)

* did the amalagamate

* rm duplicate includes

* make amalgamate again

* reorder

* amalgamate

* moved it above

* amalgamate

---------

Co-authored-by: Jordan <jordan-hoang@users.noreply.github.com>
Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

tests/src/unit-concepts.cpp

@@ -20,7 +20,6 @@ TEST_CASE("concepts")
         // a, b: values of type X: json
 
         // TABLE 96 - Container Requirements
-
         // X::value_type must return T
         CHECK((std::is_same<json::value_type, json>::value));