i18n Angular index.html does not link to appropriate subfolder

[Blake GH]

Installing Evergreen with different language support revealed an issue with Angular. This command:

ng build --configuration=production

does build the cs-CZ folder as well as the en-US folder. Found in:
../../web/eg2

But the index.html file includes lines like this:

<script src="/eg2/main.eaa9f97ec648c706.js" type="module"></script>

Lacking the locale (cs-CZ) - Evergreen will default to whatever the RewriteRule line is configured for:

RewriteRule ^/eg2/(.*) https://%{HTTP_HOST}/eg2/en-US/$1 [NE,R=307,L]

Therefore, the Angular interfaces will still show en-US, even when the URL on the browser is

/eg2/cs-CZ/staff/splash

[Bill Erickson (berick)]

Here's a work in progress branch:

https://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/berick/lp2032430-ang-locale-build-repairs

It tweaks the angular.json config file to better handle the install location for locales.

It also includes cs-CZ in the environment files, but that's just for testing this branch. We probably don't want to include those by default (though I'm not sure on that).

How I got it working:

---
$ ng build --configuration=production

# Tell cs-CZ's index.html to load the cs-CZ version of the IDL.
# This part only works if the cs-CZ DTD file has been created
# (with make LOCALE=cs-CZ install) and deployed at
# /openils/var/web/opac/locale/cs-CZ/fm_IDL.dtd

$ sed -i s/IDL2js\"/IDL2js?locale=cs-CZ\"/g ../../web/eg2/cs-CZ/index.html
---

Some notes:

1. building in non-production mode does not create the cs-CZ translations. Not sure why.
2. The cs-CZ UI is funky in places. Some strings are just missing, i.e. no fallback en-US translation. Not sure what this is about either.