Fix typo for maintaining consistency

[nujabes403]

There are some code which is not consistent another codes. For example,

1) Separation key & colon

• When defining property of object, all codes have a space between key and :.

Good example)

    RPC: RPC,
    HTTPProvider: HTTPProvider,
    KeyPair: KeyPair,

Bad example) There are some code which is not, like Tx : Tx,

2) Separation comma & argument

• When separating arguments with comma, add space between , and argument.

Good example)

c.pushBytes(this.sig, true);

Bad example)

this.sig = Buffer.from(nacl.sign(info, keyPair.seckey)).slice(0,64);

After this PR, all codes have consistency for 1) Separation key & colon, 2) Separation comma & argument

[nujabes403]

Pleas take a look @flybikeGx @sswsdsn :)