feat: Add bucket schema management commands (#52)

* feat: update generated client to include schema-management APIs
* feat: implement interfaces to decode flags and CSV
* feat: implement decoders for different measurement schema column formats
* feat: extend bucket CLI commands to support schema type property
* feat: add CLI commands to manage measurement schema
* test: add unit tests for bucket schema create, update and list commands

internal/cmd/bucket_schema/csv.go

@@ -0,0 +1,35 @@
+package bucket_schema
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/gocarina/gocsv"
+	"github.com/influxdata/influx-cli/v2/internal/api"
+)
+
+type csvColumn struct {
+	Name     string                 `csv:"name"`
+	Type     api.ColumnSemanticType `csv:"type"`
+	DataType *api.ColumnDataType    `csv:"data_type,omitempty"`
+}
+
+func decodeCSV(r io.Reader) ([]api.MeasurementSchemaColumn, error) {
+	var cols []csvColumn
+	gocsv.FailIfUnmatchedStructTags = true
+	err := gocsv.Unmarshal(r, &cols)
+	if err != nil {
+		return nil, fmt.Errorf("failed to decode CSV: %w", err)
+	}
+
+	rows := make([]api.MeasurementSchemaColumn, 0, len(cols))
+	for i := range cols {
+		c := &cols[i]
+		rows = append(rows, api.MeasurementSchemaColumn{
+			Name:     c.Name,
+			Type:     c.Type,
+			DataType: c.DataType,
+		})
+	}
+	return rows, nil
+}