Resolve "[feature] include new keywords by OGS v6.4.4"

Closes #82, #81, and #80

See merge request !60

78 packrat to renv

See merge request !59

[benchmark] local benchmark tests

Closes #73

See merge request !57

[base] add OGS v643 parameters to prj_process

Closes #74

See merge request !56

    prj_chemical_system is a class that represents the
    tag chemical_reaction. This tag defined chemical reactions
    for a the chemical_solver of type SelfContained, new in OGS643.
    the class prj_chemical_system was then updated be used for the
    two types of solvers: SelfContained and Phreeqc.

    aperture_size
    numerical_stabilization

[base] update package to OGS6.4.2

Closes #61, #72, and #71

See merge request !55