[Civl] Consolidation of pure procedures and actions

[shazqadeer]

1. Introduce pure actions in the same spirit as pure procedures
2. Introduction of computation happens only via invocation of pure actions and procedures
3. Type checking of actions with respect to global accesses and calls to other atomic actions is simplified; all actions are treated in the same manner; global variables may no longer be accessed in actions at the introduction layer of the variable
4. Linear primitives are modeled as pure procedures (without bodies)
5. Parameters across linear primitives are made consistent; inout parameter is always at position 0
6. Miscellaneous bug fixes