aws-crt-cpp: add version 0.18.8 and suppport conan v2

[toge]

Specify library name and version: aws-crt-cpp/*

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• I've read the guidelines for contributing.
• I've followed the PEP8 style guides for Python code in the recipes.
• I've used the latest Conan client version.
• I've tried at least one configuration locally with the conan-center hook activated.

[conan-center-bot]

All green in build 1 (85a502df36acefd5ed0157e957100ba31bb1b967):

• aws-crt-cpp/0.17.12@:
  All packages built successfully! (All logs)

• aws-crt-cpp/0.14.3@:
  All packages built successfully! (All logs)

• aws-crt-cpp/0.17.23@:
  All packages built successfully! (All logs)

• aws-crt-cpp/0.18.8@:
  All packages built successfully! (All logs)