opt: remove bound and loop unrolling in quote (begin to use clang13)

[liuq19]

Through calculating the max size of the quoted buffer, remove lots of branch and use loop unrolling.

performance

name                          old time/op    new time/op    delta
Encoder_Generic_Sonic_Std       49.2µs ± 2%    46.8µs ± 1%   -4.95%  (p=0.000 n=9+9)
Encoder_Generic_Sonic_StdNot    32.8µs ± 2%    28.8µs ± 3%  -12.13%  (p=0.000 n=10+8)
Encoder_Escaped_Sonic_StdNot    83.9µs ± 3%    71.4µs ± 7%  -14.86%  (p=0.000 n=10+10)
Encoder_Binding_Sonic_Std       8.31µs ± 3%    6.87µs ± 3%  -17.32%  (p=0.000 n=10+10)
Encoder_Binding_Sonic_StdNot    7.56µs ± 5%    5.82µs ± 4%  -23.08%  (p=0.000 n=10+10)
Encoder_Small_Sonic_StdNot      74.0µs ± 1%    54.0µs ± 1%  -26.94%  (p=0.000 n=10+10)

name                          old speed      new speed      delta
Encoder_Generic_Sonic_Std      265MB/s ± 2%   279MB/s ± 1%   +5.20%  (p=0.000 n=9+9)
Encoder_Generic_Sonic_StdNot   398MB/s ± 2%   451MB/s ± 1%  +13.32%  (p=0.000 n=10+7)
Encoder_Escaped_Sonic_StdNot  1.35GB/s ± 2%  1.59GB/s ± 6%  +17.55%  (p=0.000 n=10+10)
Encoder_Binding_Sonic_Std     1.57GB/s ± 3%  1.90GB/s ± 3%  +20.95%  (p=0.000 n=10+10)
Encoder_Binding_Sonic_StdNot  1.72GB/s ± 5%  2.24GB/s ± 3%  +29.94%  (p=0.000 n=10+10)
Encoder_Small_Sonic_StdNot     328MB/s ± 1%   450MB/s ± 1%  +36.88%  (p=0.000 n=10+10)

name           old time/op    new time/op    delta
EncodeLoad-16    12.4µs ± 8%     9.2µs ± 5%  -26.13%  (p=0.000 n=10+10)
EncodeLoad-16  1.05GB/s ± 7%  1.42GB/s ± 5%  +35.30%  (p=0.000 n=10+10)
EncodeLoad-16    9.48kB ± 0%    9.48kB ± 0%     ~     (p=0.087 n=10+10)