WIP: refactor web mainthread implementation in rust

[PupilTong]

@coderabbitai summary

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).
• Changeset added, and when a BREAKING CHANGE occurs, it needs to be clearly marked (or not required).

[changeset-bot]

⚠️ No Changeset found

Latest commit: 5e999e3

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[codecov]

Codecov Report

❌ Patch coverage is 72.44163% with 956 lines in your changes missing coverage. Please review.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...re-wasm/src/main_thread/element_apis/event_apis.rs	0.00%	232 Missing ⚠️
...m/web-core-wasm/src/main_thread/mts_global_this.rs	0.00%	114 Missing ⚠️
...b-core-wasm/src/main_thread/style/style_manager.rs	0.00%	95 Missing ⚠️
...re-wasm/src/template/raw_template/json_template.rs	0.00%	91 Missing ⚠️
...asm/src/main_thread/element_apis/component_apis.rs	0.00%	84 Missing ⚠️
...-core-wasm/src/main_thread/element_apis/element.rs	0.00%	76 Missing ⚠️
...ore-wasm/src/main_thread/element_apis/tree_apis.rs	0.00%	72 Missing ⚠️
...re-wasm/src/main_thread/element_apis/style_apis.rs	0.00%	71 Missing ⚠️
...core-wasm/src/template/decoded/decoded_template.rs	0.00%	53 Missing ⚠️
...orm/web-core-wasm/src/template/template_manager.rs	0.00%	27 Missing ⚠️
... and 5 more

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