[Core] Made Condition::GetIntegrationMethod const

[EduardGomezEscandell]

This PR changes the function signature from

virtual IntegrationMethod Condition::GetIntegrationMethod();

to

virtual IntegrationMethod Condition::GetIntegrationMethod() const;

Deprecation warning
This breaks the API so a deprecation warning has been added for some time (See #9789).

@KratosMultiphysics/all :

• This PR will be merged on April 19th, 2022.
• Applications in the CI run have been adapted.
• Any other applications and forks will break.

🆕 Changelog

• Makes GetIntegrationMethod method of Condition const
• Changed overrides to const

How to fix my condition?
If this change breaks any of your Conditions, simply add the const in your GetIntegrationMethod declaration in the .h header file:

- IntegrationMethod GetIntegrationMethod() override
+ IntegrationMethod GetIntegrationMethod() const override

You will also need to modify the method definition in the cpp source file if it is separate from the declaration:

- IntegrationMethod YourCondition::GetIntegrationMethod() {
+ IntegrationMethod YourCondition::GetIntegrationMethod() const {

[AlejandroCornejo]

@loumalouomega I've seen some of your implementations. Just for you to know

[loumalouomega]

@loumalouomega I've seen some of your implementations. Just for you to know

Okay, sorry for the previous message, I thought this was al another pr

[roigcarlo]

Approving on behalf of the https://github.com/orgs/KratosMultiphysics/teams/technical-committee.

Please merge the other one first.

[EduardGomezEscandell]

@KratosMultiphysics/all
A reminder that this PR will be merged right after easter. You will be affected if:

• Your application is not in the CI.
• You have your own fork.

AND

• You have overloaded Condition::GetIntegrationMethod