Some minor improvements on GetDetOffsetsMultiPeaks

[Wenduo Zhou]

It is found that sometime most of the spectra can have exactly same fit windows. On the other hand, it takes long time to generate a TableWorkspace containing millions rows in such as for Corelli in python script. Therefore, it will be better for FitwindowTableWorkspace of GetDetOffsetsMultiPeaks accept universal fit windows for all detectors.

Improve the documentation of GetDetOffsetsMultiPeaks.

[Wenduo Zhou]

Refs #9856. Made improvement on fit windows and doc.

Including

1. Add support of default fit windows to FitwindowTableWorkspace, as

well as the unit test;

2. Improve the doc.

Changeset: 7befc15ae13880404f024e44c4f36bd67f42dce8

[Wenduo Zhou]

Made minor mod to doc. Refs #9856.

Changeset: 4c6524ad47b2f3f914de9cfea20fc811a9e51306

[Wenduo Zhou]

Refs #9856. Made improvement on fit windows and doc.

Including

1. Add support of default fit windows to FitwindowTableWorkspace, as

well as the unit test;

2. Improve the doc.

Changeset: e9513593c7a1c423474a94012e95a0d613c0a834

[Wenduo Zhou]

Made minor mod to doc. Refs #9856.

Changeset: d44087e8e60821b3a6f40d146deb5136b97db2ce

[Wenduo Zhou]

For testers

The change from this ticket is to enable the various sizes of peak fit window on different spectra. It is an expansion to original setup that all spectra have the same fit windows for peaks at same d-spacing. And the new feature is applied in the case that the resolution of different detectors varies significantly.

For testing, please look at the source codes and the new unit test for the new feature. You can make a workspace with multiple spectra, each of which contains 2 or 3 peaks but with different resolution. Then you can set up a table workspace for fit windows.

[Harry Jeffery]

Merge remote-tracking branch 'origin/feature/9856_getdetoffsets_minor_mod'

Full changeset: ​29241d4e13bbd16c09b6084401dec4c693c95b44

[Stuart Campbell]

This ticket has been transferred to github issue ​10698