Refs #9589. Cleaned up documentation for PoldiAutoCorrelation.

Added usage examples, checked summary and properties, expanded description and added example spectra.
Merge remote-tracking branch 'origin/master' into feature/9589_check_documentation_sinq_poldi
Refs #9589. Removed cleanup section from PoldiAutoCorrelation docs.

It became unnecessary after merging the changes from master.
Refs #9589. Added usage example for PoldiMerge.

It required another data file to make sense.
Refs #9589. Cleaned up documentation of PoldiPeakSearch.
Refs #9589. Updated docs for legacy POLDI algorithms.

This documentation will not be changed until final decisions about their further treatment have been made.
Refs #9589. Added usage example for PoldiFitPeaks1D.
Refs #9859. Added note to PoldiPeakSearch docs, moved PoldiProjectRun
Refs #9589. Changed category of PoldiFitPeaks1D.
Merge remote-tracking branch 'origin/master' into feature/9589_check_documentation_sinq_poldi
Refs #9589. Usage examples for LoadSINQ and LoadSINQFile.
Refs #9589. Removed one more redundancy from legacy POLDI algorithms.
Refs #9589. Fixed LoadSINQ path problem.

When the standard SINQ-paths are not available, LoadSINQ returned without setting the output workspace properly. This commit fixes that behavior and makes the doc-test pass as well.
Refs #9589. Fixing sphinx warnings in PoldiProjectRun-docs.
Refs #9589. Moved data files to UsageData directory.
Merge remote-tracking branch 'origin/feature/9589_check_documentation_sinq_poldi'