server: uniform whitespace handling in rpc calls

[niklasad1]

Builds on #1080

We are already throwing away calls that begins with more than 127 whitespace characters in the HTTP server so let's do the same for the WS part as well.

In addition as we already know how many whitespace characters to skip these bytes are not needed and might speed up deserialization.

[niklasad1]

benches with 10 000 starting whitespaces.

jsonrpsee_types_deserialize_whitespace
                        time:   [4.6532 µs 4.6558 µs 4.6589 µs]
                        change: [+0.6001% +0.6798% +0.7723%] (p = 0.00 < 0.05)
                        Change within noise threshold.
Found 15 outliers among 100 measurements (15.00%)
  9 (9.00%) high mild
  6 (6.00%) high severe

jsonrpsee_types_deserialize_manually_strip_whitespace
                        time:   [3.5121 µs 3.5161 µs 3.5211 µs]
                        change: [-23.348% -23.257% -23.160%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 9 outliers among 100 measurements (9.00%)
  7 (7.00%) high mild
  2 (2.00%) high severe

jsonrpsee_types_deserialize_manually_strip_whitespace_but_deserialize_entire_payload
                        time:   [8.3066 µs 8.3898 µs 8.4791 µs]
Found 26 outliers among 100 measurements (26.00%)
  13 (13.00%) low severe
  10 (10.00%) high mild
  3 (3.00%) high severe

Thus, indeed this a perf improvement