Implement most missing wasm-c-api APIs (#303) (#676)

Remove unnecessary functions and implement more APIs:
- wasm_##name##same
- wasm##name##as_ref
- wasm_ref_as##name##
- wasm_ref_delete
- wasm_module_validate
- wasm_table_get/set/size
- wasm_memory_size
- wasm_config_new
- wasm_foreign_new

And add more wasm-c-api samples, update the related documen, add more CI rules.

Signed-off-by: Wenyong Huang <wenyong.huang@intel.com>

core/iwasm/compilation/aot_emit_table.c

@@ -25,6 +25,7 @@ get_tbl_inst_offset(const AOTCompContext *comp_ctx,
 
     while (i < tbl_idx && i < comp_ctx->comp_data->import_table_count) {
         offset += offsetof(AOTTableInstance, data);
+        /* avoid loading from current AOTTableInstance */
         offset += sizeof(uint32) * aot_get_imp_tbl_data_slots(imp_tbls + i);
         ++i;
     }
@@ -37,6 +38,7 @@ get_tbl_inst_offset(const AOTCompContext *comp_ctx,
     i -= comp_ctx->comp_data->import_table_count;
     while (i < tbl_idx && i < comp_ctx->comp_data->table_count) {
         offset += offsetof(AOTTableInstance, data);
+        /* avoid loading from current AOTTableInstance */
         offset += sizeof(uint32) * aot_get_tbl_data_slots(tbls + i);
         ++i;
     }