Fix empty AST with trivia tokens

[jeparlefrancais]

When converting an empty AST with comments or spaces, this information was previously lost. Now, it is retained in the final_token block tokens.

• [x] add entry to the changelog

[github-actions[bot]]

Coverage after merging fix-empty-block-with-trivia into main will be

87.06%

Coverage Report for Changed Files

File	Stmts	Branches	Funcs	Lines	Uncovered Lines
src
ast_converter.rs	87.72%	100%	88.57%	87.68%	1003, 1022, 1052, 1076, 1093, 1125–1127, 1142, 1170, 1212, 1227, 1243–1245, 1255, 1260–1262, 1277, 1288, 1418–1420, 1481–1483, 1534–1536, 1560–1563, 1598–1600, 1628–1630, 1634–1636, 1699–1700, 1729–1731, 1738–1740, 1759–1761, 1777–1779, 1784–1786, 1847, 1852–1854, 1874, 1880–1882, 1887–1889, 1922–1927, 1951–1953, 1979, 2042, 2060–2062, 2098–2100, 2106–2109, 2139, 2153, 2157–2159, 218–220, 2213–2215, 2227–2229, 2233–2235, 2269, 235, 2352–2354, 236–237, 2374–2376, 2397–2399, 2429–2431, 2447, 2451, 2474–2476, 2488–2490, 2509–2511, 2566–2568, 2575, 265–267, 2765, 2838–2845, 2847–2854, 2856–2866, 2875, 2877–2882, 2885, 2910–2912, 2923–2925, 2942–2944, 485, 500–502, 537–539, 547, 561, 577–579, 581–582, 584–586, 599–601, 605, 614–616, 657, 668–670, 676–678, 683–686, 697, 721, 808, 812–814, 897, 921, 933, 965, 982, 986–989
parser.rs	99.27%	100%	74.19%	99.54%	37, 43, 55–59, 66
src/generator
token_based.rs	89.66%	100%	92.90%	89.37%	10, 1000–1009, 1012, 1014–1023, 1026–1027, 1043–1044, 1058–1060, 1074–1076, 1085–1087, 1096–1098, 1107–1109, 113, 1258, 130–131, 1328, 1365–1373, 1455–1464, 147–148, 1489–1491, 1493–1495, 1512–1521, 1596, 160–161, 182–183, 203–204, 2041–2042, 205, 2068–2072, 2101–2105, 2112–2116, 2318, 2322, 2335, 245, 297–301, 373–374, 380, 392, 426–427, 449–450, 466–467, 509, 582–583, 592–593, 599–600, 606, 618, 644–645, 678–679, 727–729, 747–748, 774–775, 784–785, 791–792, 798, 80, 810, 832–836, 84, 877–878, 938–945, 960–961, 970–971, 978, 991–998
src/nodes
block.rs	96.44%	100%	98.82%	95.99%	16, 19, 231–236, 25–26, 28, 31, 40, 49–50, 52, 55
token.rs	96.36%	100%	97.78%	96.04%	194, 200–202, 68, 77, 90