Improve reading of incoming data in Bzip2Decoder

Motivation:

Exclude catching IndexOutOfBoundsException in Bzip2Decoder when it receiving selectors and Huffman length from incoming flow of data because exceptions are expensive.

Modifications:

Removed try-catch blocks from Bzip2Decoder and added checks whether the ByteBuf is readable before reading next bits.

Result:

Increased speed of receiving data in Bzip2Decoder.