* seq_result` -> `seq_ok`; add `seq_err`
`seq_ok` and `seq_err` are consistent with `ok` and `err`, but produce
results sequentially.
* Accept `;;` and longer comments in the sexp parser
Currently they are just dropped, and resulting AIR has different
character positions in the error messages.
* Add "map" assertion
Lookup result in a map by service's first argument.
Testing framework for AquaVM
Its primary features are:
1. It generates services declaratively by annotation in the comments inserted just after calls.
2. Ephemeral network keeps each node's data and incoming data queue. The network can be also generated based on peer IDs featured in the script.
3. One can explicitly add additional peers and services.
The example of the script annotations:
```
(seq
(call "peer_1" ("service" "func") [] var) ; ok=42
(call "peer_2" ("service" "func") [var]) ; err={"ret_code": 1, "result":"no towel"}
)
```
Passing this script to `air_test_framework::TestExecutor::new(...)` will create a virtual network with peers "peer_1" and "peer_2" (and any peer you provide in the `TestRunParameters`), and the particular calls will return respective values.
Please note that autogenerated services use modified service name as a side channel for finding a correct value: "..{N}" is added to each service name (two dots and serial number). Be careful with service names taken from a variable.
