Presigned URL - Expiry limit from milliseconds to seconds and epoch fixes + automatic tests

[romayalon]

Explain the changes

In #8493 changes there were 2 issues -

1. In The limit expiry check we compared ms to seconds - https://github.com/noobaa/noobaa-core/pull/8493/files#diff-6057509d5491e754e912f9e7b08644473aa76a97fb526d7e1ecfce6e9e593c7dR299, fixed this issue.
2. Epoch seconds case - When req.query.Expires has value - we use Epoch date in seconds and not seconds expiry, therefore had to calculate the number of seconds between now and Expires epoch, which means: const expiry_seconds = req.query.Expires - Math.ceil(Date.now() / 1000); in order to compare the limit on epoch case correctly.
3. Added presigned url test cases for both epoch/ seconds flows in test_bucketspace.js

Issues: Fixed #xxx / Gap #xxx

1. Fixed pre signed url is not accessible after 15 mins, throws clock skew error #8490

Testing Instructions:

1. sudo NC_CORETEST=true node ./node_modules/mocha/bin/mocha /github/noobaa-core/src/test/unit_tests/test_bucketspace.js -g 'Presigned URL tests'

• Doc added/updated
• Tests added