[ui-storagebrowser] fixes file preview for non-readable file

[ramprasadagarwal]

What changes were proposed in this pull request?

• When we are not able to read the file content due to any reason, the message will be displayed to indicate that preview is not supported.

How was this patch tested?

• Added test case

Please review Hue Contributing Guide before opening a pull request.

[github-actions]

⚠️ No unit test files modified. Please ensure that changes are properly tested. ⚠️

[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
TOTAL	53603	26241	51%

Pytest Report

Tests	Skipped	Failures	Errors	Time
1108	106 💤	0 ❌	0 🔥	5m 47s ⏱️

[JohanAhlen]

Nice!

[JohanAhlen]

This could potentially change the outcome of other tests relying on mockData. Perhaps resetting it in an "beforeEach"..