Improve shoebox position determination in `IntegratePeaksShoeboxTOF`

Description of work

Improve shoebox position determination in IntegratePeaksShoeboxTOF by doing the following:

Stop smoothing the I/sigma from the shoebox convolution - this was over smoothing as the shoebox is effectively also doing some smoothing.
Use label to find contiguous regions of statistically significant I/sigma and find regions closer to predicted peak position than any other position
Get a better initial shoebox dimensions by allowing float NFHWM

Purpose of work

In reducing SXD data for Nick Funnell it was found that the shoebox would often find a region of I/sigma far away from weak peak positions - this was because it previously centred the shoebox on the maximum I/sigma, but if there was a nearby peak which wasn't in the peak table the shoebox could go to the wrong peak position. This should be fixed by (2)

There is no associated issue.

To test:

(1) Run this script change OuptutFile

ws = Load(Filename=r'SXD23767.raw', OutputWorkspace='SXD23767')
peaks = FindSXPeaksConvolve(InputWorkspace=ws, PeakFindingStrategy="IOverSigma", NCols=7, NRows=7, NFWHM=6, ThresholdIoverSigma=5)

kwargs = {"InputWorkspace": ws, "PeaksWorkspace": peaks, "OutputWorkspace": 'peaks_int', 
          "NRows": 7, "NCols": 7, "GetNBinsFromBackToBackParams": True, "NFWHM": 3, "NShoeboxInWindow": 3,
          "WeakPeakThreshold": 0, "IntegrateIfOnEdge": True, "LorentzCorrection": False,
          "OutputFile": '//olympic/Babylon5/Public/RWaite/test_shoebox.pdf'}
IntegratePeaksShoeboxTOF(**kwargs)

(2) Check the pdf - the box should be centered on the peak in the data nearest the red x

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mantidproject / mantid