Add WAL durability setting to collector

[emeroad]

# Set span wal durability. default:USE_DEFAULT
# https://hbase.apache.org/2.3/book.html#wal.durability
# USE_DEFAULT: default durability
# SKIP_WAL: skip write to WAL
# ASYNC_WAL: async write to WAL
# SYNC_WAL: sync write to WAL
# FSYNC_WAL: fsync write to WAL
collector.span.durability=USE_DEFAULT

Add WAL durability setting to improve write performance.