Rectification of windows batch-wrappers

[willend]

Free-form text area

Please describe what your PR is adding in terms of features or bugfixes:

Replace use of CMAKE_INSTALL and go for auto-detection of bin directory.

Corresponding edits for matplotlib-oriented tools are incoming in an existing PR.

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Declaration of use of AI-tools

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Development OS / boundary conditions

Please describe what OS you developed and tested your additions on, and if any special dependencies are required:

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PR Checklist for contributing to McStas/McXtrace

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• My contribution contains something else

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[willend]

Merge. Trivial edits.