surfaceTensionModels::liquidProperties: New temperature-dependent surface tension model

Description
    Temperature-dependent surface tension model in which the surface tension
    function provided by the phase Foam::liquidProperties class is used.

Usage
    \table
        Property     | Description               | Required    | Default value
        phase        | Phase name                | yes         |
    \endtable

    Example of the surface tension specification:
    \verbatim
        sigma
        {
            type    liquidProperties;
            phase   water;
        }
    \endverbatim

for use with e.g. compressibleInterFoam, see
tutorials/multiphase/compressibleInterFoam/laminar/depthCharge2D