feat(eventstore): add search table (#8191)

# Which Problems Are Solved

To improve performance a new table and method is implemented on
eventstore. The goal of this table is to index searchable fields on
command side to use it on command and query side.

The table allows to store one primitive value (numeric, text) per row.

The eventstore framework is extended by the `Search`-method which allows
to search for objects.
The `Command`-interface is extended by the `SearchOperations()`-method
which does manipulate the the `search`-table.

# How the Problems Are Solved

This PR adds the capability of improving performance for command and
query side by using the `Search`-method of the eventstore instead of
using one of the `Filter`-methods.

# Open Tasks

- [x] Add feature flag
- [x] Unit tests
- [ ] ~~Benchmarks if needed~~
- [x] Ensure no behavior change
- [x] Add setup step to fill table with current data
- [x] Add projection which ensures data added between setup and start of
the new version are also added to the table

# Additional Changes

The `Search`-method is currently used by `ProjectGrant`-command side.

# Additional Context

- Closes https://github.com/zitadel/zitadel/issues/8094

internal/eventstore/eventstore.go

@@ -11,6 +11,7 @@ import (
 	"github.com/zitadel/logging"
 
 	"github.com/zitadel/zitadel/internal/api/authz"
+	"github.com/zitadel/zitadel/internal/zerrors"
 )
 
 // Eventstore abstracts all functions needed to store valid events
@@ -19,8 +20,9 @@ type Eventstore struct {
 	PushTimeout time.Duration
 	maxRetries  int
 
-	pusher  Pusher
-	querier Querier
+	pusher   Pusher
+	querier  Querier
+	searcher Searcher
 
 	instances         []string
 	lastInstanceQuery time.Time
@@ -62,8 +64,9 @@ func NewEventstore(config *Config) *Eventstore {
 		PushTimeout: config.PushTimeout,
 		maxRetries:  int(config.MaxRetries),
 
-		pusher:  config.Pusher,
-		querier: config.Querier,
+		pusher:   config.Pusher,
+		querier:  config.Querier,
+		searcher: config.Searcher,
 
 		instancesMu: sync.Mutex{},
 	}
@@ -127,6 +130,20 @@ func (es *Eventstore) AggregateTypes() []string {
 	return aggregateTypes
 }
 
+// FillFields implements the [Searcher] interface
+func (es *Eventstore) FillFields(ctx context.Context, events ...FillFieldsEvent) error {
+	return es.searcher.FillFields(ctx, events...)
+}
+
+// Search implements the [Searcher] interface
+func (es *Eventstore) Search(ctx context.Context, conditions ...map[FieldType]any) ([]*SearchResult, error) {
+	if len(conditions) == 0 {
+		return nil, zerrors.ThrowInvalidArgument(nil, "V3-5Xbr1", "no search conditions")
+	}
+
+	return es.searcher.Search(ctx, conditions...)
+}
+
 // Filter filters the stored events based on the searchQuery
 // and maps the events to the defined event structs
 //
@@ -262,6 +279,22 @@ type Pusher interface {
 	Push(ctx context.Context, commands ...Command) (_ []Event, err error)
 }
 
+type FillFieldsEvent interface {
+	Event
+	Fields() []*FieldOperation
+}
+
+type Searcher interface {
+	// Search allows to search for specific fields of objects
+	// The instance id is taken from the context
+	// The list of conditions are combined with AND
+	// The search fields are combined with OR
+	// At least one must be defined
+	Search(ctx context.Context, conditions ...map[FieldType]any) (result []*SearchResult, err error)
+	// FillFields is to insert the fields of previously stored events
+	FillFields(ctx context.Context, events ...FillFieldsEvent) error
+}
+
 func appendEventType(typ EventType) {
 	i := sort.SearchStrings(eventTypes, string(typ))
 	if i < len(eventTypes) && eventTypes[i] == string(typ) {