feat: add user-level parameter autofill (#11731)

This PR solves #10478 by auto-filling previously used template values in create and update workspace flows.

I decided against explicit user values in settings for these reasons:

* Autofill is far easier to implement
* Users benefit from autofill _by default_ — we don't need to teach them new concepts
* If we decide that autofill creates more harm than good, we can remove it without breaking compatibility

coderd/database/modelmethods.go

@@ -256,6 +256,10 @@ func (u User) UserDataRBACObject() rbac.Object {
 	return rbac.ResourceUserData.WithID(u.ID).WithOwner(u.ID.String())
 }
 
+func (u User) UserWorkspaceBuildParametersObject() rbac.Object {
+	return rbac.ResourceUserWorkspaceBuildParameters.WithID(u.ID).WithOwner(u.ID.String())
+}
+
 func (u GetUsersRow) RBACObject() rbac.Object {
 	return rbac.ResourceUserObject(u.ID)
 }