remove encoding for KVv2

[Monkeychip]

Description

Fixes Issue #25905. TBD if I should backport or not. It's a bug fix, but also higher risk for regressions.

• [ ] Confirmed does not regress PR fix for a similar URL decoding issue.
• [ ] Added test coverage
• [ ] Ent tests pass

Before and after video walk through.

TODO only if you're a HashiCorp employee

• [ ] Backport Labels: If this PR is in the ENT repo and needs to be backported, backport
  to N, N-1, and N-2, using the backport/ent/x.x.x+ent labels. If this PR is in the CE repo, you should only backport to N, using the backport/x.x.x label, not the enterprise labels.
  • [ ] If this fixes a critical security vulnerability or severity 1 bug, it will also need to be backported to the current LTS versions of Vault. To ensure this, use all available enterprise labels.
• [ ] ENT Breakage: If this PR either 1) removes a public function OR 2) changes the signature of a public function, even if that change is in a CE file, double check that applying the patch for this PR to the ENT repo and running tests doesn't break any tests. Sometimes ENT only tests rely on public functions in CE files.
• [ ] Jira: If this change has an associated Jira, it's referenced either in the PR description, commit message, or branch name.
• [ ] RFC: If this change has an associated RFC, please link it in the description.
• [ ] ENT PR: If this change has an associated ENT PR, please link it in the description. Also, make sure the changelog is in this PR, not in your ENT PR.