SQL Expressions: Re-implement feature using go-mysql-server (#99521)

* Under feature flag `sqlExpressions` and is experimental
* Excluded from arm32
* Will not work with the Query Service yet
* Does not have limits in place yet
* Does not working with alerting yet
* Currently requires "prepare time series" Transform for time series viz
 
---------

Co-authored-by: Sam Jewell <sam.jewell@grafana.com>

pkg/expr/sql/frame_db.go

@@ -0,0 +1,65 @@
+//go:build !arm
+
+package sql
+
+import (
+	mysql "github.com/dolthub/go-mysql-server/sql"
+	"github.com/grafana/grafana-plugin-sdk-go/data"
+)
+
+var dbName = "frames"
+
+// FramesDBProvider is a go-mysql-server DatabaseProvider that provides access to a set of Frames.
+type FramesDBProvider struct {
+	db mysql.Database
+}
+
+func (p *FramesDBProvider) Database(_ *mysql.Context, _ string) (mysql.Database, error) {
+	return p.db, nil
+}
+
+func (p *FramesDBProvider) HasDatabase(_ *mysql.Context, _ string) bool {
+	return true
+}
+
+func (p *FramesDBProvider) AllDatabases(_ *mysql.Context) []mysql.Database {
+	return []mysql.Database{p.db}
+}
+
+// NewFramesDBProvider creates a new FramesDBProvider with the given set of Frames.
+func NewFramesDBProvider(frames data.Frames) mysql.DatabaseProvider {
+	fMap := make(map[string]mysql.Table, len(frames))
+	for _, frame := range frames {
+		fMap[frame.RefID] = &FrameTable{Frame: frame}
+	}
+	return &FramesDBProvider{
+		db: &framesDB{
+			frames: fMap,
+		},
+	}
+}
+
+// framesDB is a go-mysql-server Database that provides access to a set of Frames.
+type framesDB struct {
+	frames map[string]mysql.Table
+}
+
+func (db *framesDB) GetTableInsensitive(_ *mysql.Context, tblName string) (mysql.Table, bool, error) {
+	tbl, ok := mysql.GetTableInsensitive(tblName, db.frames)
+	if !ok {
+		return nil, false, nil
+	}
+	return tbl, ok, nil
+}
+
+func (db *framesDB) GetTableNames(_ *mysql.Context) ([]string, error) {
+	s := make([]string, 0, len(db.frames))
+	for k := range db.frames {
+		s = append(s, k)
+	}
+	return s, nil
+}
+
+func (db *framesDB) Name() string {
+	return dbName
+}