refactor: use matches! macro as suggested by clippy

[mikavilpas]

I started reading the codebase and noticed cargo clippy suggests some refactorings that can be done. If these seem like a good idea, they can be included (most are basically autofixes)

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Running cargo clippy suggested using the matches! macro in various places. There are many other fixes, but this commit focuses on just using the matches! macro.

92  warning: match expression looks like `matches!` macro
   --> crates/emmylua_parser/src/grammar/lua/stat.rs:33:5
    |
 33 | /     match p.current_token() {
 34 | |         LuaTokenKind::TkElse
 35 | |         | LuaTokenKind::TkElseIf
 36 | |         | LuaTokenKind::TkEnd
 ...  |
 39 | |         _ => false,
 40 | |     }
    | |_____^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_like_matches_macro
    = note: `#[warn(clippy::match_like_matches_macro)]` on by default
 help: try
    |
 33 ~     matches!(p.current_token(), LuaTokenKind::TkElse
 34 +         | LuaTokenKind::TkElseIf
 35 +         | LuaTokenKind::TkEnd
 36 +         | LuaTokenKind::TkEof
 37 +         | LuaTokenKind::TkUntil)
    |