fix: update returned Job with API-determined location in getMetadata

[laljikanjareeya]

reqOpts of getMetadata has been set while initializing job object(constructor), once object initialized the there wasn't any impact of job's location changes in getMetadata's query string.

Location is passing currently in query string:

const bigquery = new BigQuery();
const job = new Job(bigquery, 'jobId', {
    location: 'australia-southeast1'
});

job.getMetadata((err, metadata, apiResponse) => { });

query string is undefined

const bigquery = new BigQuery();
const job = new Job(bigquery, 'jobId');
job.location = 'australia-southeast1';
job.getMetadata((err, metadata, apiResponse) => { });

Fixes #896

[codecov]

Codecov Report

Merging #900 (a422fc7) into master (a099bf0) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #900   +/-   ##
=======================================
  Coverage   98.68%   98.68%           
=======================================
  Files           9        9           
  Lines        7145     7155   +10     
  Branches      441      440    -1     
=======================================
+ Hits         7051     7061   +10     
  Misses         94       94           

Impacted Files	Coverage Δ
src/job.ts	100.00% <100.00%> (ø)

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[mbyrne00]

I’m not sure if this suits the style/structure of your tests or not but a high level test to create a job in Australia (or any other non-us) and wait for it to complete would highlight the exact use case nicely to the next developer. Whichever combination caused job not found. I see the tests seem quite targeted for specific functions so if this doesn’t suit or is too much hassle feel free to ignore.

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