feat: Add compression support for wasm binary

[bigsaltyfishes]

This is an attempt to add compression support for wasm binary.

• Add data-compression-algorithm and data-compression-level attributes.
• Enable gzip compression by default on release build, can be disabled by set data-compression-level="0".
• Use DecompressionStream API to decompress at runtime.

[ctron]

Thanks for the PR. I guess this could be a valuable addition. There are two things:

• I think it would make sense doing a quick check/proof on how much this would safe. Showing one or two examples.
• It looks like this is missing out on the else when using the more complex initializer. It also seems to repeat code from the initializer, which does something similar. Maybe it's time to collapse both, and have the "non initializer" version be a special (simpler) form of the initializer version?

[bigsaltyfishes]

Thanks for the PR. I guess this could be a valuable addition. There are two things:

• I think it would make sense doing a quick check/proof on how much this would safe. Showing one or two examples.
• It looks like this is missing out on the else when using the more complex initializer. It also seems to repeat code from the initializer, which does something similar. Maybe it's time to collapse both, and have the "non initializer" version be a special (simpler) form of the initializer version?

I've merged repeat code and add missing compression support for custom initializer. Here are the file size savings with compression enabled. All examples were built with the release profile. By default, gzip compression is enabled with the default compression level:

Example	Raw	wasm-opt processed (opt-level='z')	Compressed
initializer	35 KB	23 KB	11 KB
leptos	137 KB	93 KB	36 KB
yew	450 KB	307 KB	104 KB
My Blog (Leptos 0.8)	1349 KB	819 KB	330 KB

All examples save about 50% to 70% in size.