[BUG] UncorEncounterModel sample and track functions require three specific dynamic variables and fails when acceleration, climb rate, or turn rate is not present

### Description

`UncorEncounterModel` class methods of `sample` and subsequently `track` assume the Bayesian network has dynamic variables for acceleration (`'\dot v'`), climb rate (`'\dot h'`), and turn rate (`'\dot \psi'`). While this is true for most models, the unconventional balloon and weather balloon models only have a dynamic variable for climb rate and not for acceleration or turn rate.

### Reproducibility

Change `RUN_uncor` to use the unconventional model parameter file of balloon_v1.txt or weatherballoon_v1.txt. The script will throw an error when calling the `sample` method of `UncorEncounterModel`.

```matlab
parameters_filename = [getenv('AEM_DIR_BAYES') filesep 'model' filesep 'balloon_v1.txt'];
```

### Expectation

Update the `UncorEncounterModel` class methods of `sample` and `track` to handle any combination of dynamic variables of acceleration, climb rate, and turn rate.

### Additional

Upon resolving this issue, remove the warning issued by the `UncorEncounterModel` class constructor for the balloon models.

Start with the UncorEncounterModel class and its sample and track methods, then reproduce the failure by changing RUN_uncor to use balloon_v1.txt or weatherballoon_v1.txt. Done means both methods handle any combination of acceleration, climb-rate, and turn-rate variables, and the constructor warning for balloon models is removed.

Written by the indexing model from the issue text.