fix(search_family): Add options test for the FT.AGGREGATE command

[BagritsevichStepan]

related to the #4204

1. Fix some small issues during parsing of the several SEARCH methods
2. Remove using builder in Parse* methods.
   It was a bad decision to use it because, in some cases, we were returning an error with builder->SendError(...). However, in those cases, we were not handling parser errors with parser->Error(). As a result, debug builds were crashing because of this check:

CmdArgParser::~CmdArgParser() {
  DCHECK(!error_.has_value()) << "Parsing error occured but not checked";
}

Now, we ensure that parsing errors are processed in all cases.
3. Add options test for the FT.AGGREGATE command

[BorysTheDev]

I think you don't need it

[BagritsevichStepan]

Why?
For ParseSchema, we return false. It is the last option that should be parsed.

[BorysTheDev]

you already have a check if (!parse_result) so parse_result.value() is always exist

[BagritsevichStepan]

parse_result is io::Error<bool>, so when I prove if (!parse_result), I prove that no error occurred. When I check if (!parse_result.value()), I prove that the returned result is false.