Additional Functions Coverage for Reader Xls (#3371)

PR #3340 increased coverage in Reader Xls for most functions. Some of the omissions from that PR (see below) were intended from the start. However, the set of (BINOMDIST, EXPONDIST, GAMMADIST, NORMDIST, POISSON, WEIBULL, and FIXED) were not intended to be omitted; they just did not seem to work. Having had time to research, it appears that the problem is not those functions themselves, but rather the use of Boolean constants as function arguments (see issue #3369). Knowing that, it is possible to add those missing functions back in, just taking care to use `0` or `1` or `TRUE()` or `FALSE()` rather than boolean constants as arguments. No update to source or test code; just adding a few new cells to an Xls spreadsheet.

Functions still omitted because they return array results:
- GROWTH
- LINEST
- LOGEST
- MINVERSE
- MMULT
- TRANSPOSE
- TREND

Functions still omitted because they are not implemented in PhpSpreadsheet:
- BAHTTEXT
- CELL
- FREQUENCY
- GETPIVOTDATA