feat: enable type safety for Func and Service IDL types

[ilbertt]

Description

Adds generic type arguments to Func and Service IDL types. This should be backwards compatible.

How Has This Been Tested?

Same tests should still pass. TypeScript should still build.

Checklist:

• My changes follow the guidelines in CONTRIBUTING.md.
• The title of this PR complies with Conventional Commits.
• I have edited the CHANGELOG accordingly.
• I have made corresponding changes to the documentation.

[github-actions]

size-limit report 📦

Path	Size
@dfinity/agent	47.91 KB (0%)
@dfinity/assets	52.94 KB (0%)
@dfinity/auth-client	19.38 KB (0%)
@dfinity/candid	13.22 KB (0%)
@icp-sdk/core	91 B (0%)
@dfinity/identity	18.81 KB (0%)
@dfinity/identity-secp256k1	33.03 KB (0%)
@dfinity/principal	4.44 KB (0%)
@dfinity/use-auth-client	58.77 KB (0%)