* YNU-496: remove signer requirement from public requests (#456)

The PR removes the signer parameter from multiple read-only query message creation functions across the SDK and integration tests. These functions now return unsigned JSON request strings instead of signed payloads, while mutation operations retain signing capability.

* YNU-496: fix(sdk): update api types (#457)

* fix(sdk): v0.5.1 types

* feat(sdk): bump version to 0.5.2

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Co-authored-by: Anton Filonenko <phil@yellow.org>