Enable the semantic version mechanism for WAMR (#1374)

Use the semantic versioning (https://semver.org) to replace the current date
versioning system, which is more general and is requested by some developers,
e.g. issue #1357.

There are three parts in the new version string:
- major. Any incompatible modification on ABIs and APIs will lead to an increment
  in the value of major, which mainly includes: AOT calling conventions, AOT file
  format, wasm_export.h, wasm_c_api.h, and so on.
- minor. It represents new features, including MVP/POST-MVP features, libraries,
  WAMR private ones, and so one.
- patch. It represents patches.

The new version will start from 1.0.0. Update the help info and version showing for
iwasm and wamrc.

core/iwasm/include/wasm_export.h

@@ -1137,6 +1137,12 @@ WASM_RUNTIME_API_EXTERN const uint8_t *
 wasm_runtime_get_custom_section(wasm_module_t const module_comm,
                                 const char *name, uint32_t *len);
 
+
+/**
+ * Get WAMR semantic version
+ */
+WASM_RUNTIME_API_EXTERN void
+wasm_runtime_get_version(uint32_t *major, uint32_t *minor, uint32_t *patch);
 /* clang-format on */
 
 #ifdef __cplusplus