Drop package_name argument in KedroSession.create in 0.19

[noklam]

Description

• Drop package_name argument in KedroSession.create in 0.19
• Updating all the test cases without the project_name
• Remove all internal calls with package_name

Context

• The package_name argument provided in KedroSession.create() doesn't do anything, which is confusing to users. This argument should be removed, but since that is a breaking change it will happen in 0.19
• The workaround to run a run within a session is valid, but it's important to note that bootstrap_project is only meant for configuring a project that hasn't been packaged. When working with a packaged project configure_project should be used instead.
• The problem with the main() method is that it currently returns an exit code, so downstream processes can't do anything with it.

Originally posted by @MerelTheisenQB in #1423 (comment)

[SajidAlamQB]

Completed in: #3372