CLDSRV-992: Build the uploadPartCopy fixtures once per suite, not per test

Both `uploadPartCopy` describes in the PartNumber tests rebuild a large MPU
fixture in a beforeEach, although all four of their tests only issue a
GetObject. Each rebuild moves roughly 200 MB: completeMPU uploads ten 5 MB
parts one at a time with async.eachSeries, createMPUAndPutTwoParts copies that
50 MB object and then puts a 50 MB body, and the overwrite variant adds a 5 MB
part and a second 50 MB UploadPartCopy. Doing that twice per describe, once for
each read-only test, is what pushes the hook past the 40 s mocha timeout on the
s3c backend.

Move the setup to `before` and the DeleteObject cleanup to `after`. The fixture
is identical for both tests in each describe, and the enclosing describe creates
the bucket in its own `before` and drops it in `after`, so the fixture safely
outlives the individual tests. Halves the data moved by these two describes and
removes the redundant rebuild, rather than raising the timeout.

Clears CLDSRV-992 row F4 (run 33630581671) and the timeout half of row F8
(run 33647777908, fixed for the 9.2 line separately).

Issue: CLDSRV-992

Author: anurag4DSB

tests/functional/aws-node-sdk/test/object/get.js

@@ -908,7 +908,7 @@ describe('GET object', () => {
                 const partOneBody = Buffer.concat(bufs, partOneSize);
                 const partTwoBody = Buffer.alloc(partSize, 4);
 
-                beforeEach(done => async.waterfall([
+                before(done => async.waterfall([
                     next => completeMPU(orderedPartNumbers, next),
                     next => createMPUAndPutTwoParts(partTwoBody, next),
                     (uploadId, ETags, next) =>
@@ -931,7 +931,7 @@ describe('GET object', () => {
                         })).then(() => next()).catch(next),
                 ], done));
 
-                afterEach(async () => {
+                after(async () => {
                     await s3.send(new DeleteObjectCommand({
                         Bucket: bucketName,
                         Key: copyPartKey,
@@ -955,7 +955,7 @@ describe('GET object', () => {
                     Buffer.alloc(partSize, n));
                 const partTwoBody = Buffer.concat(bufs, partTwoSize);
 
-                beforeEach(done => async.waterfall([
+                before(done => async.waterfall([
                     next => completeMPU(orderedPartNumbers, next),
                     next => createMPUAndPutTwoParts(partTwoBody, next),
                     /* eslint-disable no-param-reassign */
@@ -1004,7 +1004,7 @@ describe('GET object', () => {
                         })).then(() => next()).catch(next),
                 ], done));
 
-                afterEach(async () => {
+                after(async () => {
                     await s3.send(new DeleteObjectCommand({
                         Bucket: bucketName,
                         Key: copyPartKey,