Avoid trivial move if SST file is far smaller than the target size

Greetings everyone!

I'm using `RocksDB version: 6.8.1` with many column families. I would like to grab just one CF out for examine, because i can not figure out why doesnt do the compaction what i excepted. This CF got just INSERT without any DELETE OP, and the DB got just few restarts during his life.

LOG stats about this CF:
```
** Compaction Stats [table:blocks:data] **
Level Files Size Score Read(GB) Rn(GB) Rnp1(GB) Write(GB) Wnew(GB) Moved(GB) W-Amp Rd(MB/s) Wr(MB/s) Comp(sec) CompMergeCPU(sec) Comp(cnt) Avg(sec) KeyIn KeyDrop
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
L0 1/0 2.81 MB 0.5 0.0 0.0 0.0 0.0 0.0 0.0 1.0 0.0 106.7 0.03 0.01 2 0.016 0 0
L4 27/0 63.62 MB 1.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0.00 0 0.000 0 0
L5 33/0 90.66 MB 1.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0.00 0 0.000 0 0
L6 363/0 910.27 MB 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0.00 0 0.000 0 0
Sum 424/0 1.04 GB 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 0.0 106.7 0.03 0.01 2 0.016 0 0
Int 0/0 0.00 KB 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0.00 0 0.000 0 0

** Compaction Stats [table:blocks:data] **
Priority Files Size Score Read(GB) Rn(GB) Rnp1(GB) Write(GB) Wnew(GB) Moved(GB) W-Amp Rd(MB/s) Wr(MB/s) Comp(sec) CompMergeCPU(sec) Comp(cnt) Avg(sec) KeyIn KeyDrop
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
High 0/0 0.00 KB 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 105.7 0.02 0.01 1 0.016 0 0
User 0/0 0.00 KB 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 107.7 0.02 0.00 1 0.017 0 0
Uptime(secs): 2417.6 total, 600.0 interval
Flush(GB): cumulative 0.003, interval 0.000
AddFile(GB): cumulative 0.000, interval 0.000
AddFile(Total Files): cumulative 0, interval 0
AddFile(L0 Files): cumulative 0, interval 0
AddFile(Keys): cumulative 0, interval 0
Cumulative compaction: 0.00 GB write, 0.00 MB/s write, 0.00 GB read, 0.00 MB/s read, 0.0 seconds
Interval compaction: 0.00 GB write, 0.00 MB/s write, 0.00 GB read, 0.00 MB/s read, 0.0 seconds
Stalls(count): 0 level0_slowdown, 0 level0_slowdown_with_compaction, 0 level0_numfiles, 0 level0_numfiles_with_compaction, 0 stop for pending_compaction_bytes, 0 slowdown for pending_compaction _bytes, 0 memtable_compaction, 0 memtable_slowdown, interval 0 total count
```
Options for this CF:
```
[CFOptions "table\:blocks\:data"]
sample_for_compression=0
compaction_pri=kMinOverlappingRatio
merge_operator=nullptr
compaction_filter_factory=nullptr
memtable_factory=SkipListFactory
memtable_insert_with_hint_prefix_extractor=nullptr
comparator=leveldb.BytewiseComparator
target_file_size_base=134217728
max_sequential_skip_in_iterations=8
compaction_style=kCompactionStyleLevel
max_bytes_for_level_base=67108864
bloom_locality=0
write_buffer_size=16777216
compression_per_level=
memtable_huge_page_size=0
max_successive_merges=0
arena_block_size=2097152
memtable_whole_key_filtering=false
target_file_size_multiplier=1
max_bytes_for_level_multiplier_additional=1:1:1:1:1:1:1
num_levels=7
min_write_buffer_number_to_merge=1
max_write_buffer_number_to_maintain=0
max_write_buffer_number=2
compression=kSnappyCompression
level0_stop_writes_trigger=36
level0_slowdown_writes_trigger=20
compaction_filter=nullptr
level0_file_num_compaction_trigger=2
max_compaction_bytes=3355443200
compaction_options_universal={allow_trivial_move=false;stop_style=kCompactionStopStyleTotalSize;compression_size_percent=-1;max_size_amplification_percent=200;max_merge_width=4294967295;min_merge_width=2;size_ratio=1;}
memtable_prefix_bloom_size_ratio=0.000000
max_write_buffer_size_to_maintain=0
hard_pending_compaction_bytes_limit=274877906944
ttl=0
table_factory=BlockBasedTable
soft_pending_compaction_bytes_limit=68719476736
prefix_extractor=nullptr
bottommost_compression=kDisableCompressionOption
force_consistency_checks=false
paranoid_file_checks=true
compaction_options_fifo={allow_compaction=false;max_table_files_size=1073741824;}
max_bytes_for_level_multiplier=10.000000
optimize_filters_for_hits=false
level_compaction_dynamic_level_bytes=true
inplace_update_num_locks=10000
inplace_update_support=false
periodic_compaction_seconds=0
disable_auto_compactions=false
report_bg_io_stats=false

[TableOptions/BlockBasedTable "table\:blocks\:data"]
pin_top_level_index_and_filter=true
enable_index_compression=false
read_amp_bytes_per_bit=21474836480
format_version=5
block_align=false
metadata_block_size=4096
block_size_deviation=10
partition_filters=false
block_size=32768
index_block_restart_interval=1
no_block_cache=true
checksum=kCRC32c
whole_key_filtering=true
index_shortening=kShortenSeparators
data_block_index_type=kDataBlockBinarySearch
index_type=kBinarySearch
verify_compression=false
filter_policy=nullptr
data_block_hash_table_util_ratio=0.750000
pin_l0_filter_and_index_blocks_in_cache=false
block_restart_interval=16
cache_index_and_filter_blocks_with_high_priority=true
cache_index_and_filter_blocks=false
hash_index_allow_collision=true
flush_block_policy_factory=FlushBlockBySizePolicyFactory
```
So the target file size should be 128MB, but when we calculate level nr 6 file sizes then i have average 2.5mb. Optimal it should be just about 8 files in the level nr 6.

Thanks for the help!