Wasm service is down and a generator for the ELF executables selection list should be introduced

[ChinYikMing]

Wasm service down after merging #474. The reason is that multiple ELF executables are being placed in the build/linux-x86-softfp and build/riscv32 directories, whereas wasm service expects the ELF executables to be located in the build/ directory.

[ChinYikMing]

Additionally, the more ELF executables there are, the longer the list of ELF executables becomes in the web page UI. Therefore, a list generator could be utilized to dynamically update the content of the ELF executables list in the web page UI.