#484: feat: add support for command [JSON.ARRLEN]

[jujiale]

hello:
this pr is link #484

add json.arrlen command. refer to redis json.arrlen
add unit tests in eval_test.go

because JSON.ARRLEN never change the json value, so I think there is no need to add integration test in tests/json_test.go

the json.arrlen in redis behavior as below:
`

127.0.0.1:6379> JSON.SET user $ '{"age":13,"high":1.60,"pet":null,"language":["python","golang"],"flag":false,"partner":{"name":"tom","language":["rust"]}}'
OK
127.0.0.1:6379> JSON.ARRLEN user
(error) ERR Path '.' does not exist or not an array
127.0.0.1:6379> JSON.ARRLEN user $
1) (nil)
127.0.0.1:6379> JSON.ARRLEN user $.*
1) (nil)
2) (nil)
3) (nil)
4) (integer) 2
5) (nil)
6) (nil)
127.0.0.1:6379> JSON.ARRLEN user $..language
1) (integer) 2
2) (integer) 1
127.0.0.1:6379> JSON.ARRLEN user
(error) ERR Path '.' does not exist or not an array

`

in dice, keep consistent

[jujiale]

@JyotinderSingh
hello. in dice test workflow. I find that TestExecuteQueryWithIncompatibleTypes/NullValue sometimes it result failed,as this pr run test failed.
I test in my local env, there is one failed in fivetimes, please have a check. thanks.

[JyotinderSingh]

@JyotinderSingh

hello. in dice test workflow. I find that TestExecuteQueryWithIncompatibleTypes/NullValue sometimes it result failed,as this pr run test failed.

I test in my local env, there is one failed in fivetimes, please have a check. thanks.

I will take a look

[JyotinderSingh]

@jujiale please pull the latest changes, I have removed this test since it was irrelevant.

[jujiale]

@jujiale please pull the latest changes, I have removed this test since it was irrelevant.

done. Thank you for your prompt reply

[JyotinderSingh]

Thanks @jujiale for adding support for JSON.ARRLEN! The changes look good and well tested.
LGTM.