Feat/seqgen grammar v2

[joswig]

Closes #1361

[shaheerk94]

@joswig I see ground epochs have been implemented like so:

`@GROUND_EPOCH("Name","+3:00") @REQUEST_BEGIN("request.name") # Description Text
  C CMD_0 1 2 3
  @METADATA "foo" "bar"
  @MODEL "a" 1 "00:00:00"
  R100 CMD_1 "1 2 3"
  C CMD_2 1 2 3
  R100 CMD_3 "1 2 3"
@REQUEST_END

I propose that we instead support ground epochs at the same level that we support absolute/relative/command complete times like so:

`E NAME+03:00:00 @REQUEST_BEGIN("request.name") # Description Text
  C CMD_0 1 2 3
  @METADATA "foo" "bar"
  @MODEL "a" 1 "00:00:00"

  R100 CMD_1 "1 2 3"

  C CMD_2 1 2 3

  R100 CMD_3 "1 2 3"

@REQUEST_END
@METADATA "sub_object" {
  "boolean": true
}

I added a space between the E and the epoch name because otherwise you end up with ENAME+03:00:00 which isn't the most readable. Maybe this is why you went with @GROUND_EPOCH instead? I do think we should try to have the ground epoch time tag match the format of the other time tags if possible. We should also support using ground epochs not just with request start times, but also on any random command, such as:

E NAME+03:01 CMD_1 "1 2 3" 

[joswig]

@joswig I see ground epochs have been implemented like so:

`@GROUND_EPOCH("Name","+3:00") @REQUEST_BEGIN("request.name") # Description Text
  C CMD_0 1 2 3
  @METADATA "foo" "bar"
  @MODEL "a" 1 "00:00:00"
  R100 CMD_1 "1 2 3"
  C CMD_2 1 2 3
  R100 CMD_3 "1 2 3"
@REQUEST_END

I propose that we instead support ground epochs at the same level that we support absolute/relative/command complete times like so:

`E NAME+03:00:00 @REQUEST_BEGIN("request.name") # Description Text
  C CMD_0 1 2 3
  @METADATA "foo" "bar"
  @MODEL "a" 1 "00:00:00"

  R100 CMD_1 "1 2 3"

  C CMD_2 1 2 3

  R100 CMD_3 "1 2 3"

@REQUEST_END
@METADATA "sub_object" {
  "boolean": true
}

I added a space between the E and the epoch name because otherwise you end up with ENAME+03:00:00 which isn't the most readable. Maybe this is why you went with @GROUND_EPOCH instead? I do think we should try to have the ground epoch time tag match the format of the other time tags if possible. We should also support using ground epochs not just with request start times, but also on any random command, such as:

E NAME+03:01 CMD_1 "1 2 3" 

What guarantees do we have on delta format? String is in the schema

[joswig]

We will address ground epoch update with the implementation of ground epoch time tags for commands

[goetzrrGit]

On thing to note is we don't have the autocomplete hooked up. Not sure if you want to do that later?

[duranb]

Is it ok if we hold off on merging this? I would like to prioritize @cohansen's refactor first. I don't expect to see many conflicts other than the globals change.