Sitop command parses the integer incorrectly

[51-code]

Describe the bug

There is a test case for this query:
| sitop 15 limit=5 foo by bar

which gives the following error:

line 46:11 mismatched input 'limit=' expecting {PIPE, COMMA, GET_FIELD_SINGLE_QUOTED, GET_FIELD_DOUBLE_QUOTED, GET_FIELD_STRING, COMMAND_SITOP_MODE_BY}

This means that the parsing is topped when reaching the limit parameter.

When looking at the parse tree, it is seen that the integer "15" is actually parsed as a FieldListType instead of a IntegerType as it should be. Limit parameter and other optional parameters are only allowed before the fieldListType, so the parser stops.

Expected behavior

Should parse the integer as an IntegerType and then continue to parsing the limit parameter (or other optional parameters).

How to reproduce

Test the query above.

Screenshots

Software version

6.1.0

Desktop (please complete the following information if relevant):

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Additional context

Needs more investigation on why the integer does not parse as an IntegerType. Having it in its own grammar rule in the command might help.

sitopSyntaxParseTest in SitopSyntaxTests.java has been disabled because of this issue in PR #52.