v0.1.51: Add new vector operations and some refactoring (#62)

* update soroban sdk

* refactor using `hostCallAux`

* refactor `vec.wast` test

* implement `vec_put`

* implement `vec_del`

* implement `vector_push_front` and some refactoring

* implement `vec_pop_front` `vec_pop_back`

* implement `vec_front` `vec_back`

* implement `vec_insert`

* implement `vec_append`

* implement `vec_slice`

* Set Version: 0.1.51

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Co-authored-by: devops <[email protected]>