refactor(iota-transaction-builder): split lib.rs into multiple files (#…

…4196)

* create package.rs, stake.rs, and utils.rs files

* moved functions publish_tx_kind, publish, upgrade_tx_kind, upgrade to package.rs file.

* moved functions request_add_stake, request_withdraw_stake, request_add_timelocked_stake, request_withdraw_timelocked_stake into stake.rs

* moved functions select_gaz, get_object_arg, input_ref, resolve_and_check_json_args, get_object_ref, get_object_ref_and_type to utils.rs

* updated lib.rs to remove the moved functions and to include stake, utils, package mod and their function use statements.

* adding clarifying comments.

* remove redundant comments.

* change use super::*; to use crate:: in pacckage.rs, stake.rs, utils.rs files.

* edited use statement to include TransactionBuilder struct to resolve errors in pr checks.

* moved use statements up with other use statements.

* adjusted 3rd party use statements in package.rs

* adjusted 3rd party use statements in stake.rs

* adjusted 3rd party use statements in utils.rs (and package, stakes)

* added changes requested my thilault-martinez here.

* removed no longer needed use statements from lib.rs

* fix(iota-transaction-builder): fix compilation, remove unused imports + fmt

* fix(iota-transaction-builder): fix unresolved link in docs

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Co-authored-by: Thoralf-M <[email protected]>
Co-authored-by: Thoralf Müller <[email protected]>