feat(api): feature flags (#7356)

* feat(api): feature API proto definitions

* update proto based on discussion with @livio-a

* cleanup old feature flag stuff

* authz instance queries

* align defaults

* projection definitions

* define commands and event reducers

* implement system and instance setter APIs

* api getter implementation

* unit test repository package

* command unit tests

* unit test Get queries

* grpc converter unit tests

* migrate the V1 features

* migrate oidc to dynamic features

* projection unit test

* fix instance by host

* fix instance by id data type in sql

* fix linting errors

* add system projection test

* fix behavior inversion

* resolve proto file comments

* rename SystemDefaultLoginInstanceEventType to SystemLoginDefaultOrgEventType so it's consistent with the instance level event

* use write models and conditional set events

* system features integration tests

* instance features integration tests

* error on empty request

* documentation entry

* typo in feature.proto

* fix start unit tests

* solve linting error on key case switch

* remove system defaults after discussion with @eliobischof

* fix system feature projection

* resolve comments in defaults.yaml

---------

Co-authored-by: Livio Spring <livio.a@gmail.com>

internal/feature/key_enumer.go

@@ -0,0 +1,86 @@
+// Code generated by "enumer -type Key -transform snake -trimprefix Key"; DO NOT EDIT.
+
+package feature
+
+import (
+	"fmt"
+	"strings"
+)
+
+const _KeyName = "unspecifiedlogin_default_orgtrigger_introspection_projectionslegacy_introspection"
+
+var _KeyIndex = [...]uint8{0, 11, 28, 61, 81}
+
+const _KeyLowerName = "unspecifiedlogin_default_orgtrigger_introspection_projectionslegacy_introspection"
+
+func (i Key) String() string {
+	if i < 0 || i >= Key(len(_KeyIndex)-1) {
+		return fmt.Sprintf("Key(%d)", i)
+	}
+	return _KeyName[_KeyIndex[i]:_KeyIndex[i+1]]
+}
+
+// An "invalid array index" compiler error signifies that the constant values have changed.
+// Re-run the stringer command to generate them again.
+func _KeyNoOp() {
+	var x [1]struct{}
+	_ = x[KeyUnspecified-(0)]
+	_ = x[KeyLoginDefaultOrg-(1)]
+	_ = x[KeyTriggerIntrospectionProjections-(2)]
+	_ = x[KeyLegacyIntrospection-(3)]
+}
+
+var _KeyValues = []Key{KeyUnspecified, KeyLoginDefaultOrg, KeyTriggerIntrospectionProjections, KeyLegacyIntrospection}
+
+var _KeyNameToValueMap = map[string]Key{
+	_KeyName[0:11]:       KeyUnspecified,
+	_KeyLowerName[0:11]:  KeyUnspecified,
+	_KeyName[11:28]:      KeyLoginDefaultOrg,
+	_KeyLowerName[11:28]: KeyLoginDefaultOrg,
+	_KeyName[28:61]:      KeyTriggerIntrospectionProjections,
+	_KeyLowerName[28:61]: KeyTriggerIntrospectionProjections,
+	_KeyName[61:81]:      KeyLegacyIntrospection,
+	_KeyLowerName[61:81]: KeyLegacyIntrospection,
+}
+
+var _KeyNames = []string{
+	_KeyName[0:11],
+	_KeyName[11:28],
+	_KeyName[28:61],
+	_KeyName[61:81],
+}
+
+// KeyString retrieves an enum value from the enum constants string name.
+// Throws an error if the param is not part of the enum.
+func KeyString(s string) (Key, error) {
+	if val, ok := _KeyNameToValueMap[s]; ok {
+		return val, nil
+	}
+
+	if val, ok := _KeyNameToValueMap[strings.ToLower(s)]; ok {
+		return val, nil
+	}
+	return 0, fmt.Errorf("%s does not belong to Key values", s)
+}
+
+// KeyValues returns all values of the enum
+func KeyValues() []Key {
+	return _KeyValues
+}
+
+// KeyStrings returns a slice of all String values of the enum
+func KeyStrings() []string {
+	strs := make([]string, len(_KeyNames))
+	copy(strs, _KeyNames)
+	return strs
+}
+
+// IsAKey returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i Key) IsAKey() bool {
+	for _, v := range _KeyValues {
+		if i == v {
+			return true
+		}
+	}
+	return false
+}