HtmlUtils is using deprecated jsoup method

[mkreidenweis]

Description of the bug

We were trying to use Vaadin 14.3.3 TestBench test together with io.github.bonigarcia webdrivermanager version 4.2.0, which depends on jsoup 1.13.1. This causes an exception during Vaadin component initialization because flow-server is using a deprecated jsoup method, which has been removed in jsoup 1.13.1

Has been deprecated since version 1.11.1: jhy/jsoup@f71712b#diff-e8dacc63f3cfadcc7f860888bbb32e56R30

Fix should be easy: Just remove the deprecated null argument from https://github.com/vaadin/flow/blob/master/flow-server/src/main/java/com/vaadin/flow/internal/HtmlUtils.java#L41
(Preferrably also for older Vaadin/Flow versions.)

Minimal reproducible example

Run a Vaadin TestBench test in a maven project with this dependency:

        <dependency>
            <groupId>io.github.bonigarcia</groupId>
            <artifactId>webdrivermanager</artifactId>
            <version>4.2.0</version>
        </dependency>

Expected behavior

It should just work like without the webdrivermanager dependency. :-)

Actual behavior

Getting this exception:

java.lang.NoSuchMethodError: 'void org.jsoup.nodes.TextNode.<init>(java.lang.String, java.lang.String)'
	at com.vaadin.flow.internal.HtmlUtils.escape(HtmlUtils.java:41)
	at com.vaadin.flow.component.grid.AbstractColumn.setHeaderText(AbstractColumn.java:170)
	at com.vaadin.flow.component.grid.HeaderRow$HeaderCell.<init>(HeaderRow.java:50)
...

Workaround

Exclude jsoup from webdrivermanager dependency:

        <dependency>
            <groupId>io.github.bonigarcia</groupId>
            <artifactId>webdrivermanager</artifactId>
            <version>4.2.0</version>
            <exclusions>
                <exclusion>
                    <groupId>org.jsoup</groupId>
                    <artifactId>jsoup</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

Versions:

- Vaadin / Flow version: 14.3.3 / 2.3.3
- Java version: 11
- OS version: Linux/Windows