- improved input validation
- using references
- more consts

Refs #24006

Update copyright headers in all files

Squashed commit of the following:

* First version of a script to manage copyright statements

re #23468

* Neatened up script, added comments

re #23488

* move script to tools directory

re #23488

* small script changes and a couple of manual file changes

re #23488

* Minor chnage to whitespace detection in regex

re #23488

* Add an excluded directory

re #23488

* remove a repeasted copyright statement in a file

re #23488

* Don't comsume the comment end if it is on the same line

re #23488

* fix error in new copright parsing

re #23488

* remove double copyrifght entry

re #23488

* Improve handling of old copyrights at the start of comments

re #23488

* remove empty comments re #23488

* exclude gsoapgenerated directories

re #23488

* Sort out greedy line matching re #23488

* improve empty comment removal

re #23488

* improve false positives

re #23488

* impressive speedup by limiting regex matching length

re #23488

* remove evil invisible non ascii character

Also upadte the copyright at the same time

re #23488

* resolve multiple copyrights in a single file

re #23488

* resolve an issue with new statement detection

re #23488

* another unprintable unicode character

re #23488

* pep updates and cmake the new copyright fit clang format

re #23488

* update already done new format headers

re #23488

* wrong type of bracket

re #23488

* Update class_maker and friends

re #23488

* Update all copyright statements

re #23488

* clang format re #23488

* flake8 warnings re #23488

* Flake8 warnings re #23488

* Exclude .cmake.in and rb.in files

re #23488

* replace missing line re #23488

* exclude .py.in files as they are flasely recognized as C++

re #23488

* another setp.py.in re #23488

* another .py.in correction re #23488

* Hopefully the last of the .py.in files re #23488

* resolve utf-8 encoding of python files and changed ABINS checksum

re #23488

* updates to unit tests that reference line numbers

re #23488

* remaining unit test files and other fixes

re #23488

Update to clang-format-5 and reformat the codebase 

This uses the -fix option on clang-tidy to automatically fix all
the cases not using bool literals that have crept into Mantid.

It's more likely that the property is a PropertyWithValue<double> or
TimeSeriesProperty<double>, so put these first rather than trying all
the PropertyWithValue types before moving on to the TimeSeriesProperties.

(This has no significant effect on the performance tests)

re #17197

If value has already been found, cache it in case we need it again

Results of performance test locally (Win7 Debug):
before 1.56 s
after 0.09 s

re #17197

Test exceptions in both cases:
- string cannot be parsed
- not a numeric value or a string

Also add spaces to exception string.

re #17087

Median was missing, and Mean was implemented as TimeAveragedMean:
correct this and implement all members of the enum.

re #17087

(Strings that can be parsed as a number)

re #17087

re #17087

Tries double, int32_t, int64_t, float, uint32_t, uint64_t

re #17087

re #15289