Don't generate entries for Abstract Models in more areas (Fixes #194)

[GeoMaciolek]

(Hope the multiple edits here isn't too messy - if need be, we can roll it up into one.)

Regarding Issue #194 - the fixes pushed a few days ago in 0e1ef96 didn't handle all of the issues, so I've replicated the ``filter(model => !model.abstract)` in a few other generators:

• api_py()
• urls_py()
• index_htm()
• htmx_htm()
• serializers()

All of those seem correct to me. The one I'm less certain about is a change around line 216 in rendering.js - I'm not sure how const apps is used. This might break stuff, or it might not. My testing didn't indicate any issues, but I don't have the whole test harness working - I mostly did it by hand, so, not all code paths for sure. Help & testing would be appreciated!

    const apps = keys(this.store.getters.projectData(projectid).apps).filter(
      app_id => this.store.getters.appData(app_id) !== undefined
    ).map(app_id =>{
      const app = this.store.getters.appData(app_id)

      if (app == undefined) return

      // In the line below - I added the filter
      const models = this.get_models(app_id).filter(model => !model.abstract)

[mmcardle]

@GeoMaciolek Thanks for the PR, I will try to get to look at it soon.

[mmcardle]

So i think at this point we should create a new function

get_concrete_models(appid) {
  return this.get_models(appid).filter(model => !model.abstract)
}

and use it everywhere you have it

[GeoMaciolek]

This makes perfect sense, will do!

[mmcardle]

The const apps on line 216 is used as part of the rendering of the browsable tree in the UI, so I don't think your changes will affect this.

[GeoMaciolek]

Did as suggested; new get_concrete_models(). We even saved a few lines, replacing a couple places where you'd had multi-line versions of the filter, like below:

// ######## Old Line ~1232 ########
    const models = this.get_models(appid).filter((modelData)=> {
      // Do not include abstract models in form views
      return !modelData.abstract
    })

// ######## Changed To ########
    // Do not include abstract models in form views
    const models = this.get_concrete_models(appid)

[mmcardle]

Looks good, tests pass, testing locally