[enhancement] add index and batchsize annotations
[enhancement] add entity graph and change index annotations
[task] removed entity graph because eager fetching increase fetch time
[fix] OneToOne because meta should only reference to one resource entity
[refactoring] removed null check on extensionFieldValues

extensionFieldValues is always initialized.
rename getter and setter of extensionFieldValues.
Null check in ExtensionConverter's toScim and fromScim.
[fix] removed unique constraint

until we know how jpa merge changes and in which order
Merge pull request #138 from dacrome/performance

[task] performance