[wasm] Review temp file name generator

[maraf]

• As part WASI file system support, consider a better solution for generating temp file names.
  At the moment we are using posix-like implementation from emscripten.
  Blocked by support for temp directories: Allow mk*temp on WASI WebAssembly/wasi-libc#229

• Remove workaround introduced in [wasm] Always allocate when computing temp path #81085 after emscripten bump - [wasi] Revert "Always allocate when computing temp path" #104109

cc @pavelsavara

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Issue Details

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As part WASI file system support, consider a better solution for generating temp file names.
At the moment we are using posix-like implementation from emscripten.

cc @pavelsavara

Author:	maraf
Assignees:	-
Labels:	arch-wasm
Milestone:	8.0.0

[pavelsavara]

See also emscripten-core/emscripten#18914

[maraf]

cc @radekdoulik