Update to clang-format-5 and reformat the codebase 

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re #15289

The missing algorithm does not throw the history but prints the contents of the missing algorithm.

and in so doing eliminate use of the removed unwrap algorithm.

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>

It does not currently handle properties that don't exist when the algorithm is
initialized very well.

Load is now not a special case and any FileProperty/MultipleFileProperty
value is prefixed with r to turn then into raw strings.

by using the ADS::retrieveWS<Type>() method.

This reverts commit 3f3ed473.

This reverts commit e8376118.

Refs #3192 - all FileProperty parameters now have their values appended with an "r" in the Python script.  Modified GeneratePythonScriptTest to accommodate the changes. 

"Copy to clipboard" and "Save to file" (WS history Python script) functionality of UI now utilises the GeneratePythonScript algorithm.  

Made alteration to the constructor of AlgorithmHistoryWindow, and changed how it is called in MantidUI accordingly.

Changed heading for script output.

Refs #3501 - Fixed several warnings and an error that appeared on the non-MS compilers that occurred as a result of the previous commit.