feat(linter): implement unicorn/consistent-existence-index-check (#7262)

[unicorn/consistent-existence-index-check](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/main/docs/rules/consistent-existence-index-check.md)
for #684

---------

Co-authored-by: Cam McHenry <camchenry@users.noreply.github.com>

Author: 2 people

crates/oxc_linter/src/rules.rs

@@ -282,6 +282,7 @@ mod react_perf {
 mod unicorn {
     pub mod catch_error_name;
     pub mod consistent_empty_array_spread;
+    pub mod consistent_existence_index_check;
     pub mod consistent_function_scoping;
     pub mod empty_brace_spaces;
     pub mod error_message;
@@ -869,6 +870,7 @@ oxc_macros::declare_all_lint_rules! {
     typescript::triple_slash_reference,
     unicorn::catch_error_name,
     unicorn::consistent_empty_array_spread,
+    unicorn::consistent_existence_index_check,
     unicorn::consistent_function_scoping,
     unicorn::empty_brace_spaces,
     unicorn::error_message,