allow to use generateChangelog instead of diff to generate the sql corresponding to the jakarta annotations

[jonenst]

Describe the current behavior

the readme suggests

Another possibility is to dump the sql statements corresponding to the jpa annotations (replace DATABASE_TYPE by your database vendor, to get a list of supported types, execute the command as is):

mvn compile liquibase:dropAll liquibase:diff -Dliquibase-diff.outputFile=out.DATABASE_TYPE.sql

so we force dropAll and then run a diff against this empty database, which is a weird way to do it...

Describe the expected behavior

instead we should be able to do

mvn clean compile liquibase:generateChangeLog -Dliquibase.outputChangeLogFile=out.postgresql.sql

Describe the motivation

simplify, allow more possibilities because they may turn out to be useful

Extra Information

note: currently this is the best we can do I think but it's ugly you have to copypaste a huge property

$ mvn clean compile liquibase:generateChangeLog -Dliquibase.outputChangeLogFile=out.postgresql.sql  -Dliquibase.databaseUrl='hibernate:spring:org.gridsuite.study.server?dialect=org.hibernate.dialect.PostgreSQLDialect&hibernate.physical_naming_strategy=org.hibernate.boot.model.naming.CamelCaseToUnderscoresNamingStrategy&hibernate.implicit_naming_strategy=org.springframework.boot.orm.jpa.hibernate.SpringImplicitNamingStrategy' -Dliquibase.databaseDriver='liquibase.ext.hibernate.database.connection.HibernateDriver'

also the generateChangelog and diff produce sligtly different results (varchar vs text, uuid vs varchar(36), double precision vs float(53) this kind of things).. not sure what the implications are