Add Kotlin Support

[tmusin]

For Jmix Studio ticket https://youtrack.haulmont.com/issue/JST-1447

Enviroment:
Jmix version: 1.0.0
Jmix Studio plugin version: 1.0.NIGHTLY623-211
IntelliJ version: IDEA 2021.1.3 (Community Edition)

TC:

1. Create new Jmix project -> choose Jmix version 1.0.0 -> choose single-module-application template -> finish
2. Add id 'org.jetbrains.kotlin.jvm' version '1.4.32' to plugins in build.gradle.
3. Replace User.java with User.kt

User.kt

package your.package.name

import io.jmix.core.metamodel.annotation.JmixEntity
import io.jmix.security.authentication.JmixUserDetails
import io.jmix.core.entity.annotation.JmixGeneratedValue
import java.util.UUID
import io.jmix.core.entity.annotation.SystemLevel
import org.springframework.security.core.GrantedAuthority
import io.jmix.core.metamodel.annotation.InstanceName
import io.jmix.core.metamodel.annotation.DependsOnProperties
import javax.persistence.*
import javax.validation.constraints.Email

@JmixEntity
@Entity
@Table(name = "USER_", indexes = [Index(name = "IDX_USER__ON_USERNAME", columnList = "USERNAME", unique = true)])
class User : JmixUserDetails {
    @Id
    @Column(name = "ID")
    @JmixGeneratedValue
    var id: UUID? = null

    @Version
    @Column(name = "VERSION", nullable = false)
    var version: Int? = null

    @Column(name = "USERNAME", nullable = false)
    protected var username_: String? = null

    @SystemLevel
    @Column(name = "PASSWORD")
    protected var password_: String? = null

    @Column(name = "FIRST_NAME")
    var firstName: String? = null

    @Column(name = "LAST_NAME")
    var lastName: String? = null

    @Column(name = "EMAIL")
    var email: @Email String? = null

    @Column(name = "ACTIVE")
    var active: Boolean? = true

    @Transient
    protected var userAuthorities: Collection<GrantedAuthority?>? = null

    override fun getPassword(): String {
        return password_!!
    }

    override fun getUsername(): String {
        return username_!!
    }

    fun setUsername(username: String?) {
        this.username_ = username
    }

    fun setPassword(password: String?) {
        this.password_ = password
    }

    override fun getAuthorities(): Collection<GrantedAuthority?> {
        return if (userAuthorities != null) userAuthorities!! else emptyList()
    }

    override fun setAuthorities(authorities: Collection<GrantedAuthority?>) {
        this.userAuthorities = authorities
    }

    override fun isAccountNonExpired(): Boolean {
        return true
    }

    override fun isAccountNonLocked(): Boolean {
        return true
    }

    override fun isCredentialsNonExpired(): Boolean {
        return true
    }

    override fun isEnabled(): Boolean = active == true

    @get:DependsOnProperties("firstName", "lastName", "username_")
    @get:InstanceName
    val displayName: String
        get() = String.format(
            "%s %s [%s]", if (firstName != null) firstName else "",
            if (lastName != null) lastName else "", username_
        ).trim { it <= ' ' }
}

4. Run App

AR
Execution failed for task ':bootRun'.
Caused by: java.lang.IllegalArgumentException: MetaClass not found for class your.package.name.User.

After making the fixes, make sure that the problem does not return in a project without Java sources, and that the enhancing is running on 100% Kotlin projects.

It is also possible to encounter the error:
Entity class your.package.name.User is missing some of enhancing interfaces: PersistenceObject, PersistenceWeaved, PersistenceWeavedFetchGroups.

[tmusin]

Suggested changes in branch feature/JST-1447