Rename "Purchasing" to "Bills" and "Reference" to "Bills ID" across t… #4

Job	Run time
Build - Web UI	1m 59s
Filter	2m 1s
Style [pre-commit]	32s
Tests - API Schema Documentation	9m 50s
Style [Documentation]	55s
Tests - Full Migration [SQLite]	0s
Tests - Migrations [PostgreSQL]	0s
Tests - DB [SQLite] + Coverage 3.11	29m 20s
Tests - inventree-python	9m 7s
Style [Typecheck]	6m 49s
Tests - DB [PostgreSQL]	20m 36s
Tests - DB [SQLite] + Coverage 3.14	28m 51s
Tests - DB [MySQL]	18m 29s
Security [Zizmor]	20s
Tests - Web UI	1h 0m 17s
Tests - Performance	-1s
Push new schema	-1s
	3h 9m 4s

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