Fix silent wrong results for custom number types (#5805)

* Fix silent wrong results for custom number types

Squashed onto develop cd6b428ef (CI fixes from #5860). Original commits:

- Fix silent wrong results for custom number types
- Fix CI: build the out_of_range.407 message from string_t and fix a link
- Fix CI: diagnostics message, clang-tidy, and MinGW section limit
- Format the out_of_range.407 number without dump()
- Move the std::deque array test out of unit-regression3.cpp
- Fix clang-tidy and clang 3.4/3.5 failures in the custom number type changes
- Fix CI: cast the 128-bit unsigned value explicitly in the integer fast path

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Name the range checks of integer_fits_max/min

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

docs/mkdocs/docs/api/basic_json/to_bon8.md

@@ -37,8 +37,9 @@ With (2), the bytes written before the exception remain in the output adapter.
 
 ## Exceptions
 
-- Throws [out_of_range.407](../../home/exceptions.md#jsonexceptionout_of_range407) if `j` contains an unsigned integer
-  above 9223372036854775807, which BON8 cannot represent
+- Throws [out_of_range.407](../../home/exceptions.md#jsonexceptionout_of_range407) if `j` contains an integer outside
+  the range of int64 (an unsigned integer above 9223372036854775807, or, with a number type wider than 64 bits, any
+  integer beyond int64), which BON8 cannot represent
 - Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if `j` contains a string that is not
   valid UTF-8
 - Throws [type_error.321](../../home/exceptions.md#jsonexceptiontype_error321) if `j` or a value nested in it is