Added mjData.eq_active user input variable, for enabling/disabling the state of equality constraints.

Renamed `mjModel.eq_active` to `mjModel.eq_active0`, which now has the semantic of "initial value of `mjData.eq_active`".

Fixes #876.

PiperOrigin-RevId: 570410643
Change-Id: Id03171e751377c7cc453f143abee64239ee2e2ed

introspect/enums.py

@@ -394,15 +394,16 @@ ENUMS: Mapping[str, EnumDecl] = dict([
              ('mjSTATE_CTRL', 32),
              ('mjSTATE_QFRC_APPLIED', 64),
              ('mjSTATE_XFRC_APPLIED', 128),
-             ('mjSTATE_MOCAP_POS', 256),
-             ('mjSTATE_MOCAP_QUAT', 512),
-             ('mjSTATE_USERDATA', 1024),
-             ('mjSTATE_PLUGIN', 2048),
-             ('mjNSTATE', 12),
+             ('mjSTATE_EQ_ACTIVE', 256),
+             ('mjSTATE_MOCAP_POS', 512),
+             ('mjSTATE_MOCAP_QUAT', 1024),
+             ('mjSTATE_USERDATA', 2048),
+             ('mjSTATE_PLUGIN', 4096),
+             ('mjNSTATE', 13),
              ('mjSTATE_PHYSICS', 14),
-             ('mjSTATE_FULLPHYSICS', 2063),
-             ('mjSTATE_USER', 2016),
-             ('mjSTATE_INTEGRATION', 4095),
+             ('mjSTATE_FULLPHYSICS', 4111),
+             ('mjSTATE_USER', 4064),
+             ('mjSTATE_INTEGRATION', 8191),
          ]),
      )),
     ('mjtWarning',