ARROW-2418: [Rust] BUG FIX: reserve memory when building list
ARROW-2418: [Rust] BUG FIX: reserve memory when building list

Author: Andy Grove <andygrove73@gmail.com>

Closes #1857 from andygrove/list_reserve_mem and squashes the following commits:

a2edda2 <Andy Grove> BUG FIX: reserve memory when building list

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