Branch free parse digits

[franz1981]

It contains 3 improvements (unfinished):

• O(1) collation lookup table
• branchless/batchy parse digits
• NOT YET STARTED:

  vertx-sql-client/vertx-mysql-client/src/main/java/io/vertx/mysqlclient/impl/datatype/DataTypeCodec.java

  Line 61 in 9073da6

  public static Object decodeText(DataType dataType, int collationId, ByteBuf buffer) {

  exceed MinJumpTableSize (see https://stackoverflow.com/questions/44988841/force-tableswitch-instead-of-lookupswitch for more info): we should find a way to reduce the number of branches here or find a different way to perform it, because the branch predictor AND the JIT doesn't enjoy it

[franz1981]

Some of the proposed improvements are coming from https://github.com/cescoffier/fortune-benchmark/tree/main/fortune-reactive-mariadb/src/main/java/me/escoffier/fortune/reactive/mariadb so IMO they are not actually so valid (eg the cost of decoding in digits) , but given that I was having fun reading a nice article on it I said "why not trying implementing it?"

[tsegismont]

@franz1981 sorry for the late reply. I extracted the first commit to #1574 and will merge it soon, as it's obvious how it will improve the MySQL Client.

For the other changes, a separate PR would be better, but I understand you're not sure whether meaningful improvements would come out this.