Convert vector to doubles instead

Enables specifying sample materials without a chemical formula or atomic
number in SetSampleMaterial and MaterialBuilder. It is now enough to
specify the scattering and attenuation cross sections and number
density.

Re #21466

Input workspace history needs to be copied to output workspaces. In
the case of groups, where an output replaces an input, the input history
can disappear before we have time to copy it to the output.
Refs #24372

Co-Authored-By: peterfpeterson <peterfpeterson@gmail.com>

Since github's REST API has a separate url to check how many calls are
left, find out and log it at the information level. Refs #24339.

This now uses the new replacement string.
Also tidy raw string literals and remove unnecessary escape characters from replacement attribute

Add a replacement string in the config for Windows which uses the fully qualified address for the archive at ISIS

When a replacement is done by ICatalogInfo::transformArchivePath, the replacement prefix is being overridden by the preferred mount point based on whether an Optional is set. However, if the user property is not provided this was being set to an empty string. This commit sets it to an uninitialised optional instead.

It more closely describes the intent of the method.

This is more standard and removes the possibililty
of users to accidentally overriding the set of python
paths required by many interfaces to start.
The pythonscripts.directories config key is now empty by
default and only adds directories on starting the framework.

- changed the directory search for instruments back to only searching inside `getInstrumentDirectories()`
- created a new `FileDescriptor` function `isXML()` to determine if a file is of XML type (currently this is true if the file is Ascii and has an ".xml" extension)
- made `FileDescriptor.extension()` to always be lowercase
- created new functions `toLower()` and `toUpper()` in `Kernel::Strings` to convert input strings to lowercase/uppercase
- added a test for `LoadEmptyInstrument` where `LOKI` is loaded from instrument name