Add rendered field to TextContentBlock and update tests

[matgar26]

adding rendered property to TextContentBlock

[github-actions]

Coverage Report

Coverage after merging matgar26/fix-text-block into main will be

52.58%

Coverage Report

File	Stmts	Branches	Funcs	Lines	Uncovered Lines
lib/src
api_client.dart	74.58%	100%	100%	74.58%	143, 21, 33, 35, 37, 39–40, 42–43, 46, 48, 51–54
feed_client.dart	0%	100%	100%	0%	100, 102–104, 106, 112–114, 116–117, 123–125, 127–128, 134–135, 139, 141, 144–146, 149, 151, 158, 160–161, 163–164, 166–167, 169–170, 172–173, 175, 177–178, 183–184, 186–187, 190–191, 193, 195, 197–199, 206, 212–213, 217, 219–221, 223–224, 226–227, 230–231, 236–237, 242, 245, 249–251, 254–255, 261–262, 265, 270–271, 277–278, 280–282, 286–287, 290, 294, 297–298, 300–302, 306–307, 310, 314, 317–318, 320–322, 326–327, 330, 334, 337–338, 340–342, 346–347, 350, 354, 357–358, 360–362, 364–365, 370–371, 374, 378, 381–382, 384–386, 390–391, 394, 398, 401–402, 404–406, 41, 410, 413–414, 416–420, 423–424, 426–427, 431, 434–435, 437–441, 444–445, 447–448, 452, 455–456, 458–459, 46, 460–462, 465–466, 468–469, 47, 473, 476, 480–482, 487–488, 49, 491–493, 495–499, 50, 501–502, 504, 51, 510–512, 520–529, 533–539, 54, 540, 547–549, 57–58, 60–61, 86, 88, 90–92, 95–97
knock.dart	51.28%	100%	100%	51.28%	101, 104–105, 108, 112–113, 117–119, 122, 124, 62–64, 66, 93, 96–98
preferences_client.dart	5.26%	100%	100%	5.26%	14, 22, 24–26, 28, 30, 33–35, 37–38, 41–44, 47–48
user_client.dart	64.52%	100%	100%	64.52%	14–16, 18–19, 22, 30–32, 35–36, 39–40, 43–44, 47–48, 51–53, 56–57
lib/src/model
api_response.dart	87.50%	100%	100%	87.50%	27
channel.dart	100%	100%	100%	100%
feed.dart	100%	100%	100%	100%
feed_options.dart	100%	100%	100%	100%
preferences.dart	100%	100%	100%	100%
recipient.dart	100%	100%	100%	100%
user.dart	91.30%	100%	100%	91.30%	66–67
feed_extensions.dart	100%	100%	100%	100%
feed_response.dart	100%	100%	100%	100%
knock_object.dart	100%	100%	100%	100%
lib/src/util
retry.dart	100%	100%	100%	100%
date_time.dart	100%	100%	100%	100%
arguments.dart	0%	100%	100%	0%	7