Fix keystore secrets parsing when values contain commas.

[cmacknz]

The next step in fixing elastic/beats#29789 after elastic/go-ucfg#192

Update go-ucfg to allow disabling the interpretation of commas when parsing values loaded from the keystore. Adds a regression test that reproduces the problem by testing with a secret value that contains every special character instead of a basic string.

The next step will be updating this dependency in beats to actually fix the problem there.

[elasticmachine]

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• Start Time: 2022-05-19T19:02:20.618+0000

• Duration: 8 min 57 sec

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