set client-side mode as the default in V15

[vlukashov]

When starting an app with Vaadin 15 I want the default mode for views and bootstrapping to be client-side (index.html / index.ts + client-side routing + TypeScript views) so that it's easy to try out new features added in V15.

Note: Vaadin recommends to use the latest long-term support (LTS) version in any production project. V15 is not an LTS version, thus it's OK to make an experimental feature the default option there. It's still possible to change this default by adding the -Dvaadin.clientSideMode=false system property.

DoD:

• If the vaadin.clientSideMode property is not set, it's assumed to be true by default and the bootstrap happens using IndexHtmlRequestHandler instead of BootstrapHandler.
• The Vaadin Platform snapshot that includes the version of Flow with this change passes the build.
  First and foremost that includes updating all starters listed in the Update maven starters build. Each starter needs to run in the default mode (without requiring the -Dvaadin.clientSideMode=false flag). It's enough if routing remains fully server-side and the change only concerns the bootstrapping.
  • bakery-app-starter-flow-spring CCDM: use v15 alpha bakery-app-starter-flow-spring#953
  • beverage-starter-flow CCDM: use v15 snapshot beverage-starter-flow#437
  • bookstore-starter-flow CCDM: use v15 snapshot bookstore-starter-flow#193
  • skeleton-starter-flow: CCDM: use v15 skeleton-starter-flow#236
  • skeleton-starter-flow-spring: CCDM: use v15 snapshot skeleton-starter-flow-spring#234
  • component-starter-flow: CCDM: use v15 snapshot npm-addon-template#135
  • skeleton-starter-flow-cdi: CCDM: use v15 snapshot skeleton-starter-flow-cdi#114
  • base-starter-flow-osgi => this starter doesn't currently work in v14
  • business-app-starter-flow CCDM: use v15 snapshot business-app-starter-flow#78
  • invoice-editor-flow CCDM: use v15 snapshot ui-examples#79
  • addon-starter-flow CCDM: use v15 snapshot addon-template#25

[manolo]

Closing this ticket, problem in bakery should be tracked separately