feat(parser): Add conditional support inside each blocks

- Modify parseEachBody method in StatementParser to handle conditional tags
- Enable if/else, elseif, and not conditions within each loops
- Maintain nested conditional support inside iterations
- Preserve existing each block functionality

Example:
{{#each items}}
    {{#if condition}}
        content
    {{/if}}
{{/each}}

Author: LebCit

core/STE/parser/StatementParser.js

@@ -245,6 +245,8 @@ export class StatementParser extends BaseParser {
 					})
 				} else if (this.match(TokenType.TAG_EACH)) {
 					body.push(this.parseEach())
+				} else if (this.match(TokenType.TAG_CONDITIONAL)) {
+					body.push(this.parseConditional())
 				} else {
 					const expr = this.expressionParser.parseExpression()
 					this.consume(TokenType.DOUBLE_BRACE_CLOSE, "Expect '}}' after expression.")