Wrong LOAD fields parsing in the FT.AGGREGATE and FT.SEARCH commands for JSON data

[BagritsevichStepan]

Describe the bug
We need to correctly parse the fields specified in the LOAD option for JSON data. This can be an alias or the full path to the field (JsonPath Legacy mode is not supported).

For example,

Initialize:

127.0.0.1:6379> json.set j1 . '{"value":1}'
OK
127.0.0.1:6379> ft.create index on json schema $.value as value numeric sortable
OK

Here $.value is path and 'value' is alias.

Redis:

127.0.0.1:6379> ft.aggregate index "*" LOAD 1 @value // Alias
1) (integer) 1
2) 1) "value"
   2) "1"
127.0.0.1:6379> ft.aggregate index "*" LOAD 1 value // Alias
1) (integer) 1
2) 1) "value"
   2) "1"
127.0.0.1:6379> ft.aggregate index "*" LOAD 1 $.value // JsonPath
1) (integer) 1
2) 1) "$.value"
   2) "1"
127.0.0.1:6379> ft.aggregate index "*" LOAD 1 .value // JsonPath legacy mode
1) (integer) 1
2) (empty array)

Dragonfly:

127.0.0.1:6379> ft.aggregate index "*" LOAD 1 @value
1) (integer) 1
2) 1) "$.value" // Wrong, we should return alias
   2) "1"
127.0.0.1:6379> ft.aggregate index "*" LOAD 1 value
1) (integer) 1
2) 1) "$.value" // Wrong, we should return alias
   2) "1"
127.0.0.1:6379> ft.aggregate index "*" LOAD 1 $.value
1) (integer) 1
2) 1) "$.value"
   2) "1"
127.0.0.1:6379> ft.aggregate index "*" LOAD 1 .value
1) (integer) 1
2) 1) "$.value" // Wrong
   2) "1"