Benchmark opening close

[clementetb]

This PR adds some benchmark measurements on opening and closing a Realm with generated classes.

Closes #1521

[clementetb]

Execution results from running on a emulator.

478,177   ns         252 allocs    trace    OpenRealmTestsGenerated.openRealm[OneString-schema-size-0]
880,197   ns        2264 allocs    trace    OpenRealmTestsGenerated.openRealm[OneString-schema-size-25]
1,185,180   ns        4267 allocs    trace    OpenRealmTestsGenerated.openRealm[OneString-schema-size-50]
1,451,282   ns        6265 allocs    trace    OpenRealmTestsGenerated.openRealm[OneString-schema-size-75]
1,775,976   ns        8265 allocs    trace    OpenRealmTestsGenerated.openRealm[OneString-schema-size-100]
470,350   ns         252 allocs    trace    OpenRealmTestsGenerated.openRealm[OneStringRealmList-schema-size-0]
837,543   ns        2268 allocs    trace    OpenRealmTestsGenerated.openRealm[OneStringRealmList-schema-size-25]
1,135,842   ns        4265 allocs    trace    OpenRealmTestsGenerated.openRealm[OneStringRealmList-schema-size-50]
1,527,915   ns        6264 allocs    trace    OpenRealmTestsGenerated.openRealm[OneStringRealmList-schema-size-75]
1,847,464   ns        8266 allocs    trace    OpenRealmTestsGenerated.openRealm[OneStringRealmList-schema-size-100]
479,648   ns         252 allocs    trace    OpenRealmTestsGenerated.openRealm[TenStrings-schema-size-0]
1,663,987   ns        7040 allocs    trace    OpenRealmTestsGenerated.openRealm[TenStrings-schema-size-25]
2,697,291   ns       13815 allocs    trace    OpenRealmTestsGenerated.openRealm[TenStrings-schema-size-50]
3,863,344   ns       20589 allocs    trace    OpenRealmTestsGenerated.openRealm[TenStrings-schema-size-75]
5,131,282   ns       27365 allocs    trace    OpenRealmTestsGenerated.openRealm[TenStrings-schema-size-100]
463,826   ns         252 allocs    trace    OpenRealmTestsGenerated.openRealm[TenStringRealmLists-schema-size-0]
1,881,352   ns        7041 allocs    trace    OpenRealmTestsGenerated.openRealm[TenStringRealmLists-schema-size-25]
3,128,938   ns       13815 allocs    trace    OpenRealmTestsGenerated.openRealm[TenStringRealmLists-schema-size-50]
4,272,537   ns       20589 allocs    trace    OpenRealmTestsGenerated.openRealm[TenStringRealmLists-schema-size-75]
5,920,404   ns       27364 allocs    trace    OpenRealmTestsGenerated.openRealm[TenStringRealmLists-schema-size-100]
479,138   ns         252 allocs    trace    OpenRealmTestsGenerated.openRealm[HundredStrings-schema-size-0]
10,690,978   ns       54538 allocs    trace    OpenRealmTestsGenerated.openRealm[HundredStrings-schema-size-25]
20,502,521   ns      108816 allocs    trace    OpenRealmTestsGenerated.openRealm[HundredStrings-schema-size-50]
30,413,542   ns      163087 allocs    trace    OpenRealmTestsGenerated.openRealm[HundredStrings-schema-size-75]
40,625,208   ns      217365 allocs    trace    OpenRealmTestsGenerated.openRealm[HundredStrings-schema-size-100]
484,688   ns         252 allocs    trace    OpenRealmTestsGenerated.openRealm[HundredStringRealmLists-schema-size-0]
13,937,750   ns       54539 allocs    trace    OpenRealmTestsGenerated.openRealm[HundredStringRealmLists-schema-size-25]
28,047,500   ns      108813 allocs    trace    OpenRealmTestsGenerated.openRealm[HundredStringRealmLists-schema-size-50]
45,065,625   ns      163088 allocs    trace    OpenRealmTestsGenerated.openRealm[HundredStringRealmLists-schema-size-75]
59,451,916   ns      217371 allocs    trace    OpenRealmTestsGenerated.openRealm[HundredStringRealmLists-schema-size-100]