[5.2] SEF: Enable new SEF options for new installations

[Hackwar]

Summary of Changes

This PR enables the new SEF features for new installations by default. It also changes the value of the trailingslash option. In Joomla 6.0 we want to remove the "Do nothing" option again and it would be stupid to then have to switch between the values 1 and 2 instead of 0 and 1.

Testing Instructions

Codereview?

Link to documentations

Please select:

• Documentation link for docs.joomla.org:

• No documentation changes for docs.joomla.org needed

• Pull Request link for manual.joomla.org:

• No documentation changes for manual.joomla.org needed

[brianteeman]

shouldnt the default value in the xml match the value being set in the install sql?

[Hackwar]

No, because the default for existing installations should be the current behavior, not the new behavior. If I set the default to the value in the installation SQL, then a user editing the SEF plugin, not changing anything and then saving would have the new behavior.

[SniperSister]

I have tested this item ✅ successfully on d03b7bb

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[Quy]

I have tested this item ✅ successfully on f64664b

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[Quy]

RTC

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[pe7er]

Thanks @Hackwar !