Replaced boost::spirit grammar with boost::parser

[SilkeSchomann]

Description of work

Summary of work

Replaced boost::spirit with boost::parser so that boost::optional can be removed. MatrixVectorPairParser.h was one of the last places in the Mantid code base that used boost::optional. Unfortunately, this was required by the boost::spirit parser. From boost version 1.87 on there is a new parser library in boost, boost::parser. This does not rely on boost::optional.

Fixes #39617.

To test:

Check that the unit tests are running, especially the ones for MatrixVectorPairParser.

MatrixVectorPairParser is mainly used by SymmetryOperationSymbolParser and GroupTransformation. Running code like the examples in https://docs.mantidproject.org/nightly/concepts/SymmetryGroups.html will also use the MatrixVectorPairParser and can be used for testing.

This does not require release notes because this is a change that is invisible to the user.

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[SilkeSchomann]

I have currently copied all the changes from #39698 to run the unit tests. However, it would be better to merge #39698 first, even if this PR then needs rebasing on main.