Add vendor to improve building speed.

This also adds ability to be built in network-constrained environment.

vendor/github.com/cloudwego/base64x/.gitignore

@@ -0,0 +1,30 @@
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Dependency directories (remove the comment below to include it)
+# vendor/
+
+# the result of the go build
+output*
+output/*
+
+# Files generated by IDEs
+.idea/
+*.iml
+
+# Vim swap files
+*.swp
+
+# Vscode files
+.vscode
+