update vivax clinical model

[rossaman4]

Changes to the files WHvivax.cpp, WHvivax.h and vivax.xsd

• some bugs removed (previous version of WHvivax.cpp was broken)
• probability of clinical illness updated
• different relapse classifications introduced (via vivaxClinOption, variants are related to whether the relapse can trigger illness or not based on whether there is a blood-stage infection by the same brood at the same time and whether the primary infection caused illness )
• Corresponds to manuscript "The probability of acute P vivax illness following primary infection and relapse in Papua New Guinea" (vivaxClinOptions: A1j, A2j, B1j, B2j)
• nb This is not currently a full vivax model

[acavelan]

Reviewed together with @rossaman4

[acavelan]

All checks OK. macos-12 is deprecated so the test was cancelled.