🩹 bug: use app.getString, app.GetBytes instead of utils.UnsafeString, utils.UnsafeBytes in ctx.go

[efectn]

Description

Fixes #2291

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• I have performed a self-review of my own code
• New and existing unit tests pass locally with my changes
• I tried to make my code as fast as possible with as few allocations as possible

Commit formatting:

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