This stops tests failing falsely if the assertion passed, but the
stringification itself failed as the assertion was sent to the reporter.

I don't think that stringification should be fallible, but the
overhead in compilation ended up being small enough (<0.5% on `SelfTest`)
that it might be worth implementing, in case there is more users
with weird `StringMaker`s than just MongoDB.

Closes #2980

Fixes #2685

`gmtime*` on Windows fails on dates pre 1970, and because we didn't
check the return code, we would then pass invalid `tm` struct to
`strftime` causing it to assert.

Closes #2944

* bugprone-branch-clone
* bugprone-copy-constructor-init
* bugprone-empty-catch
* bugprone-sizeof-expression
* bugprone-switch-missing-default-case
* bugprone-unused-local-non-trivial-variable
* clang-analyzer-core.uninitialized.Assign
* clang-analyzer-cplusplus.Move
* clang-analyzer-optin.cplusplus.VirtualCall
* modernize-loop-convert
* modernize-raw-string-literal
* modernize-use-equals-default
* modernize-use-override
* modernize-use-using
* performance-avoid-endl
* performance-inefficient-string-concatenation
* performance-inefficient-vector-operation
* performance-noexcept-move-constructor
* performance-unnecessary-value-param (and improve generator example)
* readability-duplicate-include
* readability-inconsistent-declaration-parameter-name
* readability-non-const-parameter
* readability-redundant-casting
* readability-redundant-member-init
* readability-redundant-smartptr-get
* readability-static-accessed-through-instance
* unused variable in amalgamted tests