Transition to Angular version 7.

Changes pushed:

http://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/berick/lp1801984-angular-7

Most of the migration was automated via tools provided by Angular. After applying the updated versions in package.json, I removed the node_modules directory, did a new 'npm install', did a dev and prod build, and tested the UI. All looks good from here.

Rebasing to master to make sure no additional changes are required...
Going to mark this high priority since all other Ang6 dev will be affected by it.

Branch rebased to current master. I also updated via npm and we are now on Angular 7.2 (w/ updated dependencies).

I also explicitly added "@nguniversal/express-engine" to resolve the intermittent ngx-cookie compile errors.

To test:
cd Open-ILS/src/eg2
rm -f node_modules
npm install
ng build --prod

I have confirmed the code also merges and works fine in rel_3_2. I added 3.2 as a target, since the Angular 7 update fixes some compile errors that have recently popped up:

ERROR in ../ngx-cookie/ngx-cookie.ts(10,23): Error during template compile of 'CookieBackendService'
  Could not resolve @nguniversal/express-engine/tokens relative to /home/berick/code/Evergreen/Open-ILS/src/eg2/node_modules/ngx-cookie/ngx-cookie.d.ts..
node_modules/rxjs/internal/types.d.ts(81,44): error TS1005: ';' expected.
node_modules/rxjs/internal/types.d.ts(81,74): error TS1005: ';' expected.
node_modules/rxjs/internal/types.d.ts(81,77): error TS1109: Expression expected.

I've also tested this code against rel_3_2, signoff here: http://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/jboyer/lp1801984-ang7-signoff / working/user/jboyer/lp1801984-ang7-signoff

All of the tests pass for me, and the new Angular UIs still work and look good.

I added my sign off and pushed to master and rel_3_2 for the future!

Thanks, Bill & Jason!