feat(catalyst-python): Added missing default values for signed doc functions

[Mr-Leshiy]

Description

Added missing default values for signed document generator functions, fixed typos.

Related Pull Requests

Needed for input-output-hk/catalyst-voices#3817

Please confirm the following checks

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream module

[github-actions]

📚 Docs Preview

The docs for this PR can be previewed at the following URL:

https://docs.dev.projectcatalyst.io/libs/feat/signed-doc-default-values

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 601/601}$ | ${\color{red}Fail: 0/601}$ |

[apskhem]

LGTM