Add the concept of an RCStr string - a "Reference Counted String". Use

these to keep track of big JSON strings that might need to be used in
multiple places at the same time with different lifetimes.  Add two
different JSON string values to each parse - one with and one without
changes.  The net result is a large reduction in the number of parses
that occur when doing an UPDATE of a indexed JSON field using
json_replace() or similar.

FossilOrigin-Name: a4c1af616e672a0d4d04f2652e645617758231598fb7161b956883512303ae87

diff --cc manifest
index 192ed6f6b305e13dff19277c6e9f213ae1a954bd,b712bbf97f39db227cd113f9a3c4ca6200bfa5bc..0cb9a5f7963229073559bbb612bc62cd85c909ca
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C It\sis\san\serror\sto\stry\sto\sinsert\sa\sBLOB\svalue\sinto\sJSON.
- D 2023-07-24T23:27:05.772
 -C Extend\sthe\senhancement\sto\sjson_set()\sand\sjson_replace().\s\sClean\sup\scruft.
 -D 2023-07-26T01:05:08.003
++C Add\sthe\sconcept\sof\san\sRCStr\sstring\s-\sa\s"Reference\sCounted\sString".\s\sUse\nthese\sto\skeep\strack\sof\sbig\sJSON\sstrings\sthat\smight\sneed\sto\sbe\sused\sin\nmultiple\splaces\sat\sthe\ssame\stime\swith\sdifferent\slifetimes.\s\sAdd\stwo\ndifferent\sJSON\sstring\svalues\sto\seach\sparse\s-\sone\swith\sand\sone\swithout\nchanges.\s\sThe\snet\sresult\sis\sa\slarge\sreduction\sin\sthe\snumber\sof\sparses\nthat\soccur\swhen\sdoing\san\sUPDATE\sof\sa\sindexed\sJSON\sfield\susing\njson_replace()\sor\ssimilar.
++D 2023-07-26T01:12:08.723
  F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
  F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
  F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@@ -2044,8 -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 327fff501e36f75d4901c520123c5ca45e0e0da1d9cc8fa8fa877ceb68c686d2
- R bdfb959c0be321608fe703b9663eda08
 -P f930b139d6db0ee799bc90397b225175103c4bf22923d1c9cbcd32509adc1738
++P 28c6e964b1e2257527df02b352f02e135f7c4b764b8b41eda6461f9538f5d042 2dbb22c75e86f2e3ced38ac14b4943570d5c2f86cd5e37e875bf0c863be28836
+ R 80113afdab5484e027b5180529a678b7
++T +closed 2dbb22c75e86f2e3ced38ac14b4943570d5c2f86cd5e37e875bf0c863be28836
  U drh
- Z 1ec3b6ff4cb1459575429b1da04d690b
 -Z dc859019c8db0487fd3e03bdb875d59d
++Z b150fbb50a544ff974ea79d1ca7ea6fb
  # Remove this line to create a well-formed Fossil manifest.

diff --cc manifest.uuid
index 9eac82e0e2441423b3181511a5fec51e130904e0,4bbeaca0dbefb11b1e6b9ef4fb1cd2d9340f74d2..c81f6e6269afe6e4c418f65e4c78fc52e58bfe82
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 28c6e964b1e2257527df02b352f02e135f7c4b764b8b41eda6461f9538f5d042
 -2dbb22c75e86f2e3ced38ac14b4943570d5c2f86cd5e37e875bf0c863be28836
++a4c1af616e672a0d4d04f2652e645617758231598fb7161b956883512303ae87