Add LOX properties

[circlexiang]

Add liquid oxygen (O2) to liquidProperties

[TimoLin]

Compilation warning:

In file included from liquidProperties/O2/O2.C:1:
liquidProperties/O2/O2.H: In constructor ‘Foam::O2::O2()’:
liquidProperties/O2/O2.H:58:20: warning: ‘Foam::O2::pv_’ will be initialized after [-Wreorder]
   58 |         NSRDSfunc1 pv_;
      |                    ^~~
liquidProperties/O2/O2.H:57:20: warning:   ‘Foam::NSRDSfunc5 Foam::O2::rho_’ [-Wreorder]
   57 |         NSRDSfunc5 rho_;
      |                    ^~~~
liquidProperties/O2/O2.C:13:1: warning:   when initialized here [-Wreorder]
   13 | Foam::O2::O2()
      | ^~~~
In file included from liquidProperties/O2/O2.C:1:
liquidProperties/O2/O2.H:68:20: warning: ‘Foam::O2::sigma_’ will be initialized after [-Wreorder]
   68 |         NSRDSfunc6 sigma_;
      |                    ^~~~~~
liquidProperties/O2/O2.H:66:20: warning:   ‘Foam::NSRDSfunc0 Foam::O2::kappa_’ [-Wreorder]
   66 |         NSRDSfunc0 kappa_;
      |                    ^~~~~~
liquidProperties/O2/O2.C:13:1: warning:   when initialized here [-Wreorder]
   13 | Foam::O2::O2()
      | ^~~~
In file included from liquidProperties/O2/O2.C:1:
liquidProperties/O2/O2.H:66:20: warning: ‘Foam::O2::kappa_’ will be initialized after [-Wreorder]
   66 |         NSRDSfunc0 kappa_;
      |                    ^~~~~~
liquidProperties/O2/O2.H:62:21: warning:   ‘Foam::NSRDSfunc14 Foam::O2::Cpg_’ [-Wreorder]
   62 |         NSRDSfunc14 Cpg_;
      |                     ^~~~
liquidProperties/O2/O2.C:13:1: warning:   when initialized here [-Wreorder]
   13 | Foam::O2::O2()