Fix codegen and macro edge cases

[k-bx]

Summary

• avoid generated FromQueryResult/model identifier collisions with fields named row or pre
• support active enums containing a variant named Error
• add an option to include generated columns during entity generation and omit PostgreSQL partial unique constraints from generated entity metadata

Validation

• cargo test -p sea-orm-macros --test derive_active_enum_test --test derive_entity_model_column_name_test
• cargo test --manifest-path sea-orm-cli/Cargo.toml --lib test_generate_entity_skips_postgres_partial_unique_constraints

[k-bx]

Implemented the review feedback in PR #3158. I replaced the generated signature in with (as requested). Commit: 62b5411.

[k-bx]

Implemented the review feedback in PR #3158. I replaced the generated TryFrom<&str> signature in ActiveEnum with std::result::Result<Self, sea_orm::DbErr> as requested.
Commit: 62b5411.

[Huliiiiii]

I'd like to merge the macro hygiene part first. Could you split the new CLI flag changes into a separate PR?

[k-bx]

Per your request, I split PR #3158: this branch now only contains macro-hygiene changes, while CLI flag changes were moved to a separate branch (commit ac991a3). I’ll open a follow-up PR from that branch for the CLI part when you want. Net diff for this PR is now: [sea-orm-macros/src/derives/active_enum.rs, ... , sea-orm-macros/tests/derive_entity_model_column_name_test.rs].

[k-bx]

Done. I split PR #3158 into two branches and opened a follow-up PR for CLI flag work.

• This PR (3158) now only has macro hygiene changes.
• CLI-only PR: Split CLI flag changes from PR #3158 #3161 (branch: echo-im-seaorm-2.0.1-fixes-cli)
• Macro-only branch commit: d8386ae (on top of 62b5411)

Original PR review fix (DbErr signature tweak) remains in this PR.

[Huliiiiii]

Thanks!