Closes #3100.

is_same_v<> for is_same<>::value
decay_t<> for decay<>::type
is_integral_v<> for is_integral<>::value
invoke_result_t<> for invoke_result<>::type

TYPED_TEST_CASE is deprecated, please use TYPED_TEST_SUITE since googletest 1.10.x.

Putting IntegrationMethod after GlobalDim enables automatic
template argument deduction for that type.

NumLib tests are still not unity build.

Saves ca. 35 unneeded includes (out of 260)
and 25s of compilation time (out of 149s).

Dmitri Naumov authored 6 years ago and Dmitri Naumov committed 4 years ago

Include spdlog via BaseLib/Logging.h, which
provides macro replacements for
ERR/DBUG/WARN/INFO...

If only file name is specified it causes a warning
about the name not to be specific enough if there is
another file with the same name, e.g.:

the name `IdealGasLaw.h' supplied as the second argument
in the \file statement matches the following input
files: ogs/MaterialLib/Fluid/Density/IdealGasLaw.h
ogs/MaterialLib/MPL/Properties/IdealGasLaw.h
Please use a more specific name by including a (larger)
part of the path!

From now on only \file w/o a name or a full path will
be allowed.

find -type f | xargs sed -i 's%\(\\file\).*%\1%'

Including
 - usage of static_cast instead of c-style cast,
 - single variable declaration per line,
 - removing const from return types
 - omit unnecessary string to char* conversions,

The used clang-tidy checks are:
google-readability-casting,
readability-const-return-type,
readability-container-size-empty,
readability-delete-null-pointer,
readability-deleted-default,
readability-else-after-return,
readability-function-size,
readability-identifier-naming,
readability-inconsistent-declaration-parameter-name,
readability-isolate-declaration,
readability-misleading-indentation,
readability-misplaced-array-index,
readability-named-parameter,
readability-redundant-*,
readability-simplify-*,
readability-static-accessed-through-instance,
readability-static-definition-in-anonymous-namespace,
readability-string-compare,
readability-uniqueptr-delete-release

Most of the current .clang-tidy contained checks:
google-explicit-constructor
google-readability-braces-around-statements
modernize-loop-convert
modernize-use-default-member-init
modernize-use-emplace
modernize-use-using
readability-braces-around-statements
readability-else-after-return
readability-named-parameter
*readability-namespace-comments
*readability-inconsistent-*
readability-redundant-member-init
readability-simplify-boolean-expr
readability-string-compare
*explicit-conversions*

Also those where the second and so forth arguments are defaulted.

The MathLib::TemplateVector3 is an exception, because of the many
required changes through the code, which relies on the implicit
conversion from TemplatePoint<T, 3> to TemplateVector3<T>.

clang-tidy '*explicit*' check.

... and also comments.

Move the test to Tests/MathLib and extract MathLib::tensorToKelvin for completness.

Clang format run on near-the-header lines.

Happy New Year