Pass the solution vectors of all coupled processes to setInitialConditions

Except the changes that mentioned in the title, this MR also presents the following improvements:

1. dropped the argument use_monolithic_scheme from [local assembler]::setInitialConditions
2. set the duplicated member getDOFTables of multiple process classes as a standalone function of NumLib to avoid code redundancy.
3. added a local function in LocalAssemblerInterface.cpp to get local solution vectors.

As a benefit of these changes, the input of the total stress for HM with the staggered scheme is enabled (a benchmark is attached).

1. Feature description was added to the changelog
2. Tests covering your feature were added?
3. Any new feature or behaviour change was documented?