add support for excludes in input dir

This adds support for `--include` and `--exclude` for directory inputs.

For instance, this is what you would want to use when passing dagger
repository as an input:

```
inputs:
    repository:
        dir:
            path: .
            exclude:
                - '**/node_modules'
                - cmd/dagger/dagger
                - cmd/dagger/dagger-debug
```

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

tests/compute/exclude/.dagger/env/default/plan/main.cue

@@ -0,0 +1,41 @@
+package testing
+
+import (
+	"dagger.io/alpine"
+	"dagger.io/dagger"
+	"dagger.io/dagger/op"
+)
+
+TestData: dagger.#Artifact
+
+_expected: """
+	/src/b.txt
+	
+	/src/foo:
+	bar.txt
+	
+	"""
+
+TestIgnore: {
+	string
+	#up: [
+		op.#Load & {from: alpine.#Image},
+		op.#Exec & {
+			args: ["sh", "-c", "ls /src/* > /out.txt"]
+			mount: "/src": from: TestData
+		},
+		op.#Export & {source: "/out.txt"},
+		op.#Exec & {
+			args: [
+				"sh",
+				"-ec",
+				"""
+				cat > /test.txt << EOF
+				\(_expected)
+				EOF
+				test "$(cat /out.txt)" = "$(cat /test.txt)"
+				""",
+			]
+		},
+	]
+}