chore: add usage tracking package (#19095)

Not used in coderd yet, see stack.

Adds two new packages:
- `coderd/usage`: provides an interface for the "Collector" as well as a stub implementation for AGPL
- `enterprise/coderd/usage`: provides an interface for the "Publisher" as well as a Tallyman implementation

Relates to https://github.com/coder/internal/issues/814

coderd/database/querier.go

@@ -522,6 +522,9 @@ type sqlcQuerier interface {
 	InsertTemplateVersionTerraformValuesByJobID(ctx context.Context, arg InsertTemplateVersionTerraformValuesByJobIDParams) error
 	InsertTemplateVersionVariable(ctx context.Context, arg InsertTemplateVersionVariableParams) (TemplateVersionVariable, error)
 	InsertTemplateVersionWorkspaceTag(ctx context.Context, arg InsertTemplateVersionWorkspaceTagParams) (TemplateVersionWorkspaceTag, error)
+	// Duplicate events are ignored intentionally to allow for multiple replicas to
+	// publish heartbeat events.
+	InsertUsageEvent(ctx context.Context, arg InsertUsageEventParams) error
 	InsertUser(ctx context.Context, arg InsertUserParams) (User, error)
 	// InsertUserGroupsByID adds a user to all provided groups, if they exist.
 	// If there is a conflict, the user is already a member
@@ -568,6 +571,11 @@ type sqlcQuerier interface {
 	RemoveUserFromAllGroups(ctx context.Context, userID uuid.UUID) error
 	RemoveUserFromGroups(ctx context.Context, arg RemoveUserFromGroupsParams) ([]uuid.UUID, error)
 	RevokeDBCryptKey(ctx context.Context, activeKeyDigest string) error
+	// Note that this selects from the CTE, not the original table. The CTE is named
+	// the same as the original table to trick sqlc into reusing the existing struct
+	// for the table.
+	// The CTE and the reorder is required because UPDATE doesn't guarantee order.
+	SelectUsageEventsForPublishing(ctx context.Context, now time.Time) ([]UsageEvent, error)
 	// Non blocking lock. Returns true if the lock was acquired, false otherwise.
 	//
 	// This must be called from within a transaction. The lock will be automatically
@@ -614,6 +622,7 @@ type sqlcQuerier interface {
 	UpdateTemplateVersionDescriptionByJobID(ctx context.Context, arg UpdateTemplateVersionDescriptionByJobIDParams) error
 	UpdateTemplateVersionExternalAuthProvidersByJobID(ctx context.Context, arg UpdateTemplateVersionExternalAuthProvidersByJobIDParams) error
 	UpdateTemplateWorkspacesLastUsedAt(ctx context.Context, arg UpdateTemplateWorkspacesLastUsedAtParams) error
+	UpdateUsageEventsPostPublish(ctx context.Context, arg UpdateUsageEventsPostPublishParams) error
 	UpdateUserDeletedByID(ctx context.Context, id uuid.UUID) error
 	UpdateUserGithubComUserID(ctx context.Context, arg UpdateUserGithubComUserIDParams) error
 	UpdateUserHashedOneTimePasscode(ctx context.Context, arg UpdateUserHashedOneTimePasscodeParams) error