fix: Update persister_oauth2.go to handle special character | coming in t…

[Ajayn84]

…he scopes as part of consent request

Url encoded and decoded while fetching values from the table, as "|" is a seperator used to store scopes

Related issue(s)

Checklist

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  introduces a new feature.
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Further Comments

[CLAassistant]

All committers have signed the CLA.

[Ajayn84]

@hperl @aeneasr @alnr request your reviews

[Ajayn84]

Links to #3829

[aeneasr]

This is a backwards incompatible change that will break all existing rows. I don't think there's appetite to fix this at the moment and the solution would need to be backwards compatible and well-tested. It's probably easier to just adjust the scope charset