Closes gh-16137

Closes gh-16136

Closes gh-16135

Closes gh-16134

Closes gh-16133

Closes gh-16132

Closes gh-16131

Closes gh-16130

Closes gh-16129

Closes gh-16128

Closes gh-16127

Closes gh-16126

Closes gh-16125

Closes gh-16124

Closes gh-16123

Closes gh-16122

Closes gh-16121

Closes gh-16120

Closes gh-16119

Closes gh-16118

Closes gh-16117

Closes gh-16109

Closes gh-16114

Closes gh-16113
Closes gh-16112
Closes gh-16111
Closes gh-15916
Closes gh-15689

This commit switches the default value for the `spring.jmx.enabled`
configuration property.
JMX is now disabled by default and can be enabled with
`spring.jmx.enabled=true`.

Closes gh-16090

* pr/16053:
  Polish "Add loadOnStartup property to EndpointServlet"
  Add loadOnStartup property to EndpointServlet

Closes gh-16053

loadOnStartup property was missing from EndpointServlet and cannot be set
inside ServletEndpointRegistrar. Now it can be set and register a Servlet
with that integer property ready to act upon registration.

See gh-16053

* pr/16094:
  Polish

Closes gh-16094

See gh-16094

Closes gh-15914

Closes gh-15382