refactor(sdk)!: rename crate rs-sdk to dash-sdk

[lklimek]

Issue being fixed or feature implemented

We agreed that Rust SDK should be named dash-sdk

What was done?

Renamed crate rs-sdk to dash-sdk - only name in Cargo.toml is changed, dir names are intact

How Has This Been Tested?

Github Actions

Breaking Changes

All references to rs_sdk MUST be replaced by dash_sdk

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have added "!" to the title and described breaking changes in the corresponding section if my code contains any
• I have made corresponding changes to the documentation if needed

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone