State channel performance

[nz-neooo]

CHANGELOGS:

1. /payg/:deployment API new header: X-Channel-Block: multiple or X-Channel-Block: single. when is multiple, it will use a multiple times signature for query without sign agian. the AUTHORIZATION keep use base64 style.

2. QueryState new encode: QueryState -> serialize to bytes -> base64 encode old encode: QueryState -> json -> serialize to bytes -> base64 encode, old still on support, but in future it will be deleted.

new encode bytes:

channel_id: [0, 32),    // u256 with big endian
indexer:    [32, 52),   // address
consumer:   [52, 72),   // address
spent:      [72, 104),  // u256 with big endian
remote:     [104, 136), // u256 with big endian
is_final:   36,         // 0 is false, 1 is true
indexer_sign:  [137..202), // signature with r, s, v
consumer_sign: [202..267), // signature with r, s, v

3. MultipleQueryState encode bytes

   active:     0,        // 0 is ok, 1 is ok, but need pay middle, 2 is failure, and need pay end
   channel_id: [1..33),  // u256 with big endian
   start:      [33..65), // u256 with big endian
   end:        [65..97), // u256 with big endian
   sign:       [97..162),// signature with r, s, v

4. /payg-pay API, use for pay with QueryState use new base64 encode style with QueryState, and put it in body. response also use base64 style.