[Experimental] add prompt mode

[koluku]

s3s run as prompt mode if you set no arguments

$ AWS_PROFILE=default AWS_REGION=ap-northeast-1 ./s3s -o test.jsonl

>>> use s3://prefix

// or 

>>> use --delve

>>> state
[s3://prefix]

// select or SELECT is "SELECT * FROM S3Object s"
>>> select

>>> select * from S3Object s where s.request = "/"

>>> exit