[4.0.0] [WIP] ETR01SDK-584: Refactor lt_ecc_ecdsa_sign (remove hashing)

[andreondra]

Description

As this PR changes the API behavior, it is draft until 4.0.0 release.

In this PR, I remove hashing from lt_ecc_ecdsa_sign. I also fix relevant test.

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• 🐛 Bug fix
• ✨ New feature
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• 📝 Documentation update
• 🔧 Build system or toolchain update
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• I opened the Pull Request to the develop branch
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