Tuva macros not set up for dispatch

[tuvaforrest]

Describe the bug
A community member is having trouble in postgres wtih the try_to_cast_date() function, and can't override it with a dispatch macro. I think its because we don't give our macros a macro_namespace argument, which dbt says is a requirement for that functionality.

To Reproduce

• create your own version of a tuva macro, e.g. try_to_cast _date
• add a dispatch config to your project

  - macro_namespace: 'the_tuva_project'
    search_order: ['your_project_name','the_tuva_project']```
- dbt build, and see that the package version is still being executed

**Expected behavior**
the overridden version should execute

**Screenshots**

**Environment**
* Package version (e.g. 0.6.0): 0.8.0
* Data warehouse (e.g. Snowflake): All

**Additional context**