Add scalar SQL function unhex().

FossilOrigin-Name: 890e9629a7480138c9c1d3acc2d1e7b3c05e0d156e5c5fba428bc1aeb790fbfb

diff --cc manifest
index 5cdbc6d6b6d3878bf2611c0ab5dd49bd6dc41623,784839752b4fa0eac4970720170868db83045453..79d0b351d364905b528d7b72354c5428346f17f4
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Fix\sa\sproblem\swith\susing\sfts3\sauxiliary\sfunctions\swith\sexpressions\slike\s"E\sAND\s...",\swhere\sE\sis\sa\sNEAR\sexpression\sthat\sconsists\sentirely\sof\sdeferred\stokens.
- D 2023-01-24T11:24:28.082
 -C Update\sunhex()\sto\sallow\sa\ssecond\sargument,\sspecifying\sa\sset\sof\scharacters\sthat\sare\spermitted\sto\sappear\sbetween\spairs\sof\shexadecimal\sdigits.
 -D 2023-01-24T17:19:47.983
++C Add\sscalar\sSQL\sfunction\sunhex().
++D 2023-01-24T20:17:43.328
  F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
  F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
  F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@@ -2043,8 -2044,8 +2044,9 @@@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a9
  F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
  F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
  F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
- P 48bb7c88787bf5de1d70cf3cc81ada38c6c02e476dbdff12c8676c6d5ee19aed
- R da240f1feb163c267019691c0e1aa949
 -P dbe424b5db33ce2c7562dfb44daf2969cf3074234cc891eb9b8d0d907faf6a78
 -R 2327d3168a15a3681a167b76648dc26a
++P 39bfae4c4698a13e07c4a0725f2790955e03b601fe64e17a000c691def1bdcb8 66c8562690b19f17972589611810e1dccad3a48777acb05208289c1f77076f71
++R e4f755d732b8075e7847f3615f7f161a
++T +closed 66c8562690b19f17972589611810e1dccad3a48777acb05208289c1f77076f71
  U dan
- Z a4ad18532eeaa7e5926d4df8858c0bf9
 -Z 1993f291d48ac6d6618af856abe5f1fa
++Z b2c1f41f5ac4263ca444db1f00dc6050
  # Remove this line to create a well-formed Fossil manifest.

diff --cc manifest.uuid
index 25705f628d6b13fb57d44cb57152bfe9239d4341,82e63a96a20e1a9b9f51cd5815b50c49c7c1e751..235a802141941f21d67b4e9d82e54c1c772287d7
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 39bfae4c4698a13e07c4a0725f2790955e03b601fe64e17a000c691def1bdcb8
 -66c8562690b19f17972589611810e1dccad3a48777acb05208289c1f77076f71
++890e9629a7480138c9c1d3acc2d1e7b3c05e0d156e5c5fba428bc1aeb790fbfb