Improve staking transaction to handle transaction Size Limit

## Description

Currently `createStakeTransaction` uses just `splitCoins` to get staking amount:
`const stakeCoin = tx.splitCoins(tx.gas, [amount]);`

Limitations:
`splitCoins` has a limit of 50 objects that it trys to merge, in the background, in order to get the specified amount.

Issues:
- If user has a large number of objects and merger of 50 coin objects is not enough to reach the specified amount.
- Reaching any of transaction protocol limits (max_tx_size_bytes, max_input_objects, max_arguments...) will throw `SizeLimitExceded` error.

Suggestions:
We should look into a possibility to batch merging objects if more than 50 are needed to fulfill the specified staking amount.
For handling the `SizeLimitExceded` error we can implement a similar solution as in timelocked staking where this case is covered.