ENH: Added new foamReport functionObject

Replaces user-supplied keywords by run-time computed values in a text file.

Usage
    Example using system/controlDict.functions:

    foamReport1
    {
        // Mandatory entries (unmodifiable)
        type            foamReport;
        libs            (foamUtilityFunctionObjects);

        template        "<system>/myTemplate.md";

        substitutions
        {
            divSchemes1
            {
                type        dictionaryValue;
                object      fvSchemes;

                entries
                {
                    divSchemes      "divSchemes";
                }
            }
            fvSolution1
            {
                type        dictionaryValue;
                path        "<system>/fvSolution";

                entries
                {
                    solver_p        "solvers/p/solver";
                    solver_p_tol    "solvers/p/tolerance";
                    solver_p_reltol "solvers/p/relTol";
                    solver_U        "solvers/U/solver";
                    solver_U_tol    "solvers/U/tolerance";
                    solver_U_reltol "solvers/U/relTol";
                }
            }
            controlDict1
            {
                type        dictionaryValue;
                path        "<system>/controlDict";

                entries
                {
                    initial_deltaT       "deltaT";
                }
            }
            continuityErrors
            {
                type        functionObjectValue;
                functionObject continuityError1;

                entries
                {
                    cont_error_local    local;
                    cont_error_global   global;
                    cont_error_cumulative cumulative;
                }
            }
        }