[ui-importer] Adds preview data page

[ramprasadagarwal]

What changes were proposed in this pull request?

• Shows the preview of the file when user selects the file source in impoter

How was this patch tested?

• Added tests

Please review Hue Contributing Guide before opening a pull request.

[github-actions]

✅ Test files were modified. Ensure that the tests cover all relevant changes

[github-actions]

Backend Code Coverage Report •

File	Stmts	Miss	Cover	Missing
apps/filebrowser/src/filebrowser
api.py	517	221	57%	79–86, 94, 96–98, 100–101, 103, 115–117, 240, 296, 303, 311, 320, 327–329, 336–339, 359–360, 362–363, 365, 369–371, 373–374, 376, 378–382, 384, 386, 388–389, 391–398, 401, 404–407, 409–413, 415, 423, 431–432, 434–435, 437, 439, 469, 471–476, 479–481, 484–488, 490–493, 507–509, 511–515, 542, 639–640, 642–643, 645–646, 648–650, 652–654, 657, 783–784, 786–787, 789–790, 792–795, 797–800, 802, 808–809, 811–813, 815, 821–822, 824, 826, 831–833, 835–836, 838–841, 843, 845, 850–851, 853, 858, 860, 866–869, 872, 874, 881, 893–894, 896, 898, 900, 906–907, 909–910, 912–913, 917–919, 921, 927–928, 930–932, 934–938, 940, 942, 947–951, 953–957, 959, 965–966, 968–972, 974, 976–977, 979, 982–984, 986, 988–989, 991
desktop/libs/indexer/src/indexer
file_format.py	388	42	89%	103, 144, 151, 155, 169, 171–173, 175, 268, 284, 372, 376, 408, 417, 464–465, 468, 486–487, 541, 559–560, 596–597, 625–633, 644, 646–647, 682, 684, 686–687, 692
TOTAL	53316	26086	51%

Pytest Report

Tests	Skipped	Failures	Errors	Time
1101	107 💤	0 ❌	0 🔥	5m 46s ⏱️