Initial values for string-typed parameters are not set from SSP

[rruusu]

Description

When an SSP contains values for string-typed parameters for FMUs, the values are never set.

Steps to reproduce the behavior

1. Create an SSP with values for string-typed parameters.
2. Import and run the SSP
3. No calls to fmi2setString() are ever made.

Expected behavior

The values provided in the SSP should be set at the start of the simulation, as occurs for real, integer and boolean variables.

Version

Observed at least on maintenance/v2.1 (c2e1bfd)