1) MuonAnalysis: fix parameters passed to MuonProcess algorithm

- LoadedTimeZero is mandatory
- DeadTimeTable should be a TableWorkspace
- Type of OutputWorkspace

2) MuonProcess: make "Mode" mandatory, but grouping table should only be
mandatory if grouping is going to be done

3) Comments and fix typo in documentation

4) Fix bug where MuonAnalysis failed to load data for different instrument

Changing the instrument clears the workspaces in the ADS (see #13616) -
so add workspaces to the ADS *after* this has occurred!

Before, workspaces were added to ADS and then the instrument was changed,
which cleared them...

The name of "MuonLoad" is now very confusing as it no longer loads data
from a NeXus file. Change it to "MuonProcess" as this better reflects what
it does.

This is also a good thing because the algorithm has changed quite a bit,
and so changing its name will avoid confusion with the old one.

Instead of throwing in exec(), validate the inputs beforehand. Moved the
validation code from IMuonAsymmetryCalculator's constructor here too.

Not necessary to specify this for CorrectAndGroup mode, but in other
modes it is mandatory (so throw exception if not specified).

TODO: various validation in ML is done by throwing exceptions. Should
implement a "validateInputs" method to do this better.

The output WS is now just a Workspace_sptr as it could be a MatrixWS or a
WS group.

Now need to modify MuonAnalysis and MuonSequentialFitDialog.

MuonLoad is going to take over the functionality of MuonCalculateAsymmetry.
Looking at where it is called in the MuonAnalysis interface, there are
three use cases (after LoadMuonNexus has been called):
- correct and group
- change bin offset, crop, rebin, calculate asymmetry
- both of the above
and these are the three choices for the "mode" input parameter.

MuonLoad now takes a workspace so that the work done in MuonAnalysis can
be done here instead. This will require calling LoadMuonNexus beforehand
both in MuonAnalysis and in MuonSequentialFitDialog. (And MuonLoad should
probably be renamed! MuonProcess?)

Replace FirstPeriod and SecondPeriod by using the given sets of summed
and subtracted periods to pass data through to MuonCalculateAsymmetry,
which can already cope with arbitrary period operations.

Grouping and correcting functions now act on all workspaces.

Verified MuonLoad's tests still pass and that the Usage example in the
documentation still works properly.

Also update MuonLoadTest to match

Pass correct input parameter to MuonCalculateAsymmetry.

Verified that all tests in MuonLoadTest pass after this change.

The converted text is stored in separate .rst files in the docs directory.
Refs #9562

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>

Also move XML for flowchart to WorkflowAlgorithms.

No grouping, DTC or any other corrections applied yet.