Making command structs digestable (#2716)

* intial move

* adding stringcmdable

* moving module commands to align with other changes

---------

Co-authored-by: ofekshenawa <104765379+ofekshenawa@users.noreply.github.com>
Co-authored-by: ofekshenawa <ofek.shenawa@redis.com>

hyperloglog_commands.go

@@ -0,0 +1,42 @@
+package redis
+
+import "context"
+
+type HyperLogLogCmdable interface {
+	PFAdd(ctx context.Context, key string, els ...interface{}) *IntCmd
+	PFCount(ctx context.Context, keys ...string) *IntCmd
+	PFMerge(ctx context.Context, dest string, keys ...string) *StatusCmd
+}
+
+func (c cmdable) PFAdd(ctx context.Context, key string, els ...interface{}) *IntCmd {
+	args := make([]interface{}, 2, 2+len(els))
+	args[0] = "pfadd"
+	args[1] = key
+	args = appendArgs(args, els)
+	cmd := NewIntCmd(ctx, args...)
+	_ = c(ctx, cmd)
+	return cmd
+}
+
+func (c cmdable) PFCount(ctx context.Context, keys ...string) *IntCmd {
+	args := make([]interface{}, 1+len(keys))
+	args[0] = "pfcount"
+	for i, key := range keys {
+		args[1+i] = key
+	}
+	cmd := NewIntCmd(ctx, args...)
+	_ = c(ctx, cmd)
+	return cmd
+}
+
+func (c cmdable) PFMerge(ctx context.Context, dest string, keys ...string) *StatusCmd {
+	args := make([]interface{}, 2+len(keys))
+	args[0] = "pfmerge"
+	args[1] = dest
+	for i, key := range keys {
+		args[2+i] = key
+	}
+	cmd := NewStatusCmd(ctx, args...)
+	_ = c(ctx, cmd)
+	return cmd
+}