PARQUET-1227: Thrift crypto metadata structures
PARQUET-1227: Thrift crypto metadata structures

Author: Gidon Gershinsky <gidon@il.ibm.com>

Closes #463 from ggershinsky/p1227-thrift-crypto-metadata and squashes the following commits:

579c319 [Gidon Gershinsky] enums -> unions
d07d708 [Gidon Gershinsky] bug fix
ee4b931 [Gidon Gershinsky] multiple keys and ciphers
8d0c179 [Gidon Gershinsky] New Thrift structures for Parquet modular encryption

Change-Id: I6430da9e5bda863aa57648bd83f45a6e626aa569

xhochy/arrow,itaiin/arrow,apache/arrow,kou/arrow,renesugar/arrow,pcmoritz/arrow,xhochy/arrow,wesm/arrow,cpcloud/arrow,laurentgo/arrow,wesm/arrow,wesm/arrow,pcmoritz/arrow,xhochy/arrow,pcmoritz/arrow,wesm/arrow,tebeka/arrow,majetideepak/arrow,cpcloud/arrow,kou/arrow,kou/arrow,itaiin/arrow,majetideepak/arrow,itaiin/arrow,laurentgo/arrow,kou/arrow,majetideepak/arrow,majetideepak/arrow,majetideepak/arrow,tebeka/arrow,kou/arrow,tebeka/arrow,icexelloss/arrow,laurentgo/arrow,xhochy/arrow,itaiin/arrow,kou/arrow,renesugar/arrow,majetideepak/arrow,icexelloss/arrow,majetideepak/arrow,pcmoritz/arrow,xhochy/arrow,apache/arrow,laurentgo/arrow,cpcloud/arrow,renesugar/arrow,xhochy/arrow,itaiin/arrow,renesugar/arrow,renesugar/arrow,kou/arrow,pcmoritz/arrow,cpcloud/arrow,apache/arrow,icexelloss/arrow,icexelloss/arrow,apache/arrow,icexelloss/arrow,icexelloss/arrow,pcmoritz/arrow,laurentgo/arrow,kou/arrow,cpcloud/arrow,renesugar/arrow,tebeka/arrow,wesm/arrow,kou/arrow,icexelloss/arrow,xhochy/arrow,tebeka/arrow,wesm/arrow,apache/arrow,wesm/arrow,pcmoritz/arrow,kou/arrow,laurentgo/arrow,apache/arrow,itaiin/arrow,pcmoritz/arrow,renesugar/arrow,icexelloss/arrow,majetideepak/arrow,pcmoritz/arrow,renesugar/arrow,wesm/arrow,wesm/arrow,majetideepak/arrow,itaiin/arrow,kou/arrow,majetideepak/arrow,majetideepak/arrow,icexelloss/arrow,cpcloud/arrow,kou/arrow,majetideepak/arrow,cpcloud/arrow,wesm/arrow,xhochy/arrow,tebeka/arrow,pcmoritz/arrow,renesugar/arrow,pcmoritz/arrow,apache/arrow,laurentgo/arrow,kou/arrow,majetideepak/arrow,renesugar/arrow,itaiin/arrow,renesugar/arrow,wesm/arrow,xhochy/arrow,xhochy/arrow,itaiin/arrow,icexelloss/arrow,renesugar/arrow,wesm/arrow,cpcloud/arrow,apache/arrow,laurentgo/arrow,cpcloud/arrow,apache/arrow,cpcloud/arrow,pcmoritz/arrow,renesugar/arrow,xhochy/arrow,icexelloss/arrow,pcmoritz/arrow,cpcloud/arrow,icexelloss/arrow,tebeka/arrow,xhochy/arrow,apache/arrow,cpcloud/arrow,wesm/arrow,tebeka/arrow,tebeka/arrow,apache/arrow,pcmoritz/arrow,wesm/arrow,itaiin/arrow,icexelloss/arrow,renesugar/arrow,itaiin/arrow,itaiin/arrow,cpcloud/arrow,laurentgo/arrow,itaiin/arrow,kou/arrow,apache/arrow,itaiin/arrow,majetideepak/arrow,itaiin/arrow,laurentgo/arrow,laurentgo/arrow,cpcloud/arrow,renesugar/arrow,pcmoritz/arrow,apache/arrow,laurentgo/arrow,xhochy/arrow,laurentgo/arrow,xhochy/arrow,apache/arrow,xhochy/arrow,laurentgo/arrow,icexelloss/arrow,majetideepak/arrow,laurentgo/arrow,tebeka/arrow