[FIXED JENKINS-34880] do not show warnings if tool installer is present in at least 1 update site (#2361)

* [JENKINS-34854] - Migrate missing Integer and Boolean properties to SystemProperties

* [JENKINS-34854] - API methods for Long variables

* [JENKINS-34854] - Migrate Long settings to SystemProperties

* [JENKINS-34854] - Leftover change (I should use Save All)

* [JENKINS-34854] - Some fixes in Long methods Javadoc and log messages

* [JENKINS-34244] Some UX improvements in the New item form
* [JENKINS-34244] Submit button has three-state behavior
* [JENKINS-34244] New helper methods were added to make easier the form validation. Focus behavior reviewed

* Handle legacy use of iconSize as a variable

When iconSize was set as a jelly variable, not passed as an attribute,
the value was not being normalized to an IconSizeClass. Fixes
JENKINS-25220.

* Evaluate attrs.iconSize explicitly.

[JENKINS-33663] - Upgrade wizard

Add Upgrade Wizard
Add 'replace' handlebars method in jenkins.js
Fix state transitions to follow a single basic pattern
Suggested plugins selected by default
Add an install state for INITIAL_SECURITY_SETUP
Removed duplicate setupWizard.js on page [FIX JENKINS-34676]
Exclude plugins which are already installed when determining platform
Change 'snooze' to not look like a 'close' button
Make sure unlock screen doesn't show up after new install
Add compatibility check when offering suggested plugins
More appropriate handling of security token filter

[JENKINS-34858] - Listed Parameters should reflect what was used when the build ran

- [x] - Avoid String concatenation
- [x] - Switch to R/W lock instead of the specialized container with a significant overhead

Align /about: automation and not just CI server

* Test process cleanup can be suppressed changing BUILD_ID variable

Jenkins is an automation server, not just a CI one.

[FIX JENKINS-34857] Don't throw Exception when Jenkins.getInstance() yields null

And provided a way for plugins to define safe parameters
by extending ParametersAction

Assign name to queue maintenance thread

[JENKINS-34833] - Installation Wizard: Allow altering the list of suggested plugins from update sites (#2348)

* [JENKINS-34833] - Installation Wizard: Allow altering the list of succested plugins from update sites

In our company we provide a custom package of Jenkins, which provides a customized set of plugins (open-source and closed-source ones). These plugins come from the custom update site.

We would like to provide custom suggestions to users of our Jenkins packages when they install Jenkins. For such purpose we would like to make the plugin suggestions list overridable by UpdateSite extensions in Jenkins.

* [JENKINS-34833] - Fix the JS Unit test (code from @kzantow)

* [JENKINS-34833] - Unit tests for SetupWizard

* [JENKINS-34833] - Address comment regarding the error propagation for the unknown version

* [JENKINS-34833] - SetupWizard::getPlatformPluginList() is not a part of the public API

* [JENKINS-34833] - Address comments from @orrc

* fix read of 'SystemProperties' values before init of the context

* fix constructor and test

* revert help-spec_fr.html

* revert help-spec_fr.html

* revert help-spec_fr.html

[JENKINS-34628] - Bundle "Font Awesome" and "Google Fints: Roboto" dependencies to prevent failures in the offline mode (#2318)

* [JENKINS-34628] Remove dependencies with external static resources

* [JENKINS-34628] License files were added

* [JENKINS-34628] Added references in the About page

* [JENKINS-32886] Pick up missing downloads

* [JENKINS-32886] Improve error handling.

[JENKINS-34755] Migrate to SystemProperties and restrict access to the engine

* [JENKINS-34681] Allow custom default plugin managers

* [JENKINS-34681] Convert remaining properties to SystemProperties.

* [JENKINS-34733] - Allow overriding Jenkins UpdateCenter by a custom implementation

* [JENKINS-34733] - Reduce the logging level for the custom update center selection

* [JENKINS-34733 and JENKINS-34674] - Use SystemProperties in the UpdateCenter