Add CodecXXX capable of updating map, list, set types in statement instead of replacing it

[dfakhritdinov]

Motivation

Using currently available EncodeXXX one cannot add/update one value in fields of type Map, List or Set, only option is override the field. CodecXXX provides access to the field value while encoding thus makes possible updating fiend based on its current value.

[coveralls]

Pull Request Test Coverage Report for Build 10741738528

Details

• 17 of 22 (77.27%) changed or added relevant lines in 4 files are covered.
• 2 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.4%) to 88.083%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
scassandra/src/main/scala/com/evolutiongaming/scassandra/UpdateByIdx.scala	3	4	75.0%
scassandra/src/main/scala/com/evolutiongaming/scassandra/UpdateByName.scala	3	4	75.0%
scassandra/src/main/scala/com/evolutiongaming/scassandra/syntax.scala	11	12	91.67%
scassandra/src/main/scala/com/evolutiongaming/scassandra/UpdateRow.scala	0	2	0.0%

Files with Coverage Reduction	New Missed Lines	%
scassandra/src/main/scala/com/evolutiongaming/scassandra/syntax.scala	1	78.79%
scassandra/src/main/scala/com/evolutiongaming/scassandra/CreateClusterJ.scala	1	78.13%

Totals
Change from base Build 10452624162:	-0.4%
Covered Lines:	680
Relevant Lines:	772

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💛 - Coveralls

[dfakhritdinov]

I will reconsider having decoding part in new Codec API:

def decode[D <: GettableByIndexData] ...

because its almost same as in existing Decode trait. Also name codec should be reconsidered as well

[mr-git]

LGTM

[mr-git]

LGTM