`Utils.ParseQueryString` already unescapes every value, and
`BaseFmt.GetQueryDecoded` unescaped it again. A value that still held a
valid percent sequence after the first pass decayed on the second: an
obfuscation password of `ob%41fs` is exported as `ob%2541fs` and imported
back as `obAfs`. Only well-formed sequences are affected, which is why the
damage is silent - `100%` and `66%ff` survive untouched.
The same function also split each pair on every `=`, and skipped the pair
unless exactly two halves came out. RFC 3986 lists `=` among the
sub-delimiters a query value may carry, so only the first one separates the
key from the value, and `HttpUtility.ParseQueryString` reads a query string
the same way. Splitting on all of them discarded a syntactically valid
pair: `?ech=AAj+DQAEAAAAAA==` was lost entirely, and so was a `plugin`
value in the non-canonical SIP002 spelling, since those are `;` separated
`key=value` lists.
v2rayN percent-encodes both on export, so its own links were never
affected; what changes is that the parser now follows the grammar instead
of discarding a pair it cannot split in two.
Splitting on the first `=` only, and reading the value the parser already
decoded, fixes both. `ParseQueryString` keeps decoding because
`ConfigHandler` reads its result directly.
`GetQueryDecoded` and `GetQueryValue` are now equivalent; they are left
separate to keep this change small, and can be collapsed if you prefer.
Introduces EchConfigList and EchForceQuery fields to ProfileItem and V2rayConfig models, updates related handlers and services to process these fields, and extends the AddServerWindow UI to allow user input for ECH configuration. Also adds localization entries for the new fields and updates extension methods for string handling.
Miheichev Aleksandr Sergeevich